IPv4
- IPv4 Addressing
- IPv4 Routing
- IPv4 Multicast Counters
- Route Management
- IPv4 Route Scale
- IP Source Guard
- DHCP Server
- DHCP Relay Global Configuration Mode
- DHCP Relay Across VRF
- DHCP Relay in VXLAN EVPN
- DHCP Snooping with Bridging
- TCP MSS Clamping
- IPv4 GRE Tunneling
- GRE Tunneling Support
- BfRuntime to Use Non-default VRFs
- IPv4 Commands
IPv4 Addressing
IPv4 Address Formats
- IP address and subnet mask: The subnet mask is a 32-bit number (dotted decimal notation) that specifies the subnet address space. The subnet address space is calculated by performing an AND operation between the IP address and subnet mask.
- IP address and wildcard mask: The wildcard mask is a 32-bit number (dotted decimal notation) that specifies the subnet address space. Wildcard masks differ from subnet masks in that the bits are inverted. Some commands use wildcard masks instead of subnet masks.
- CIDR notation: CIDR notation specifies the scope of the subnet space by using a decimal number to identify the number of leading ones in the routing prefix. When referring to wildcard notation, CIDR notation specifies the number of leading zeros in the routing prefix.
- These subnets (subnet mask and CIDR notation) are calculated identically:
10.24.154.13 255.255.255.0 10.24.154.13/24 - The defined space includes all addresses between 10.24.154.0 and 10.24.154.255. These subnets (wildcard mask and CIDR notation) are calculated identically:
124.17.3.142 0.0.0.15 124.17.3.142/28The defined space includes all addresses between 124.17.3.128 and 124.17.3.143.
IPv4 Address Configuration
Assigning an IPv4 Address to an Interface
The ip address command specifies the IPv4 address of an interface and the mask for the subnet to which the interface is connected.
Exampleswitch(config)# interface vlan 200
switch(config-if-Vl200)# ip address 10.0.0.1/24
switch(config-if-Vl200)#Assigning an IPv4 Class E Address to an Interface
The ipvr routable 240.0.0.0/4command assigns a class E addresses to an interface. When configured, the class E address traffic are routed through BGP, OSPF, ISIS, RIP, static routes and programmed to the FIB and kernel. By default, this command is disabled.
- These commands configure an IPv4 Class E (240/4) address to an interface.
switch(config)# router general switch(config-router-general)# ipv4 routable 240.0.0.0/4
Detecting duplicate IP Addresses on an Interface
The ip address duplicate detection disabled command detects any duplicate IP address on the interface. When the duplicate IP address is detected, a syslog message is generated. It helps the network operator to identify IP addresses misconfiguration. By default, this feature is enabled.
- This command disables the feature on the switch.
switch(config)# ip address duplicate detection disabled - This command enables the feature.
switch(config)# ip address duplicate detection loggingNote: Commands are in global configuration mode, and are not per VRF.
This is an example of a Syslog message, when a duplicate IP address is detected.
Mar 24 16:41:57 cd290 Arp: %INTF-4-DUPLICATE_ADDRESS_WITH_HOST: IP address 100.1.1.2
configured on interface Ethernet1/1 is in use by a host with
MAC address 00:00:01:01:00:00 on interface Ethernet1/1 in VRF defaultAddress Resolution Protocol (ARP)
Address Resolution Protocol (ARP) is a protocol that maps IP addresses to MAC addresses that local network devices recognize. The ARP cache is a table that stores the correlated addresses of the devices for which the router facilitates data transmissions.
After receiving a packet, routers use ARP to find the MAC address of the device assigned to the packet’s destination IP address. If the ARP cache contains both addresses, the router sends the packet to the specified port. If the ARP cache does not contain the addresses, ARP broadcasts a request packet to all devices in the subnet. The device at the requested IP address responds and provides its MAC address. ARP updates the ARP cache with a dynamic entry and forwards the packet to the responding device. Static ARP entries can also be added to the cache through the CLI.
Proxy ARP
Proxy ARP enables a network device (proxy) to respond to ARP requests for network addresses on a different network with its MAC address. Traffic to the destination is directed to the proxy device which then routes the traffic toward the ultimate destination.
Configuring ARP
The switch uses ARP cache entries to correlate 32-bit IP addresses to 48-bit hardware addresses. The arp aging timeout command specifies the duration of dynamic address entries in the Address Resolution Protocol (ARP) cache for addresses learned through the Layer 3 interface. The default duration is 14400 seconds (four hours).
Entries are refreshed and expired at a random time that is in the range of 80%-100% of the cache expiry time. The refresh is tried three times at an interval of 2% of the configured timeout.
Static ARP entries never time out and must be removed from the table manually.
switch(config)# interface vlan 200
switch(config-if-Vl200)# arp aging timeout 7200
switch(config-if-Vl200)# show active
interface Vlan200
arp aging timeout 7200
switch(config-if-Vl200)#The arp command adds a static entry to an Address Resolution Protocol (ARP) cache.
switch(config)# arp 172.22.30.52 0025.900e.c63c arpa
switch(config)#The arp proxy max-delay command enables delaying proxy ARP requests on the configuration mode interface. Proxy ARP is disabled by default. When enabled, the switch responds to all ARP requests, including gratuitous ARP requests, with target IP addresses that match a route in the routing table. When a switch receives a proxy ARP request, eos performs a check to send the response immediately or delay the response based on the configured maximum delay in milliseconds (ms).
Example
Use the following command to set a delay of 500ms before returning a response to a proxy ARP request.
switch(config)#arp proxy max-delay 500msGratuitous ARP
Gratuitous ARP packets are broadcast by a device in response to an internal change rather than as a response to an ARP request. The gratuitous ARP packet is a request packet (no reply expected) that supplies an unrequested update of ARP information. In a gratuitous ARP packet, both the source and destination IP addresses are the IP of the sender, and the destination MAC address is the broadcast address (ff:ff:ff:ff:ff:ff).
Gratuitous ARP packets are generated to update ARP tables after an IPv4 address or a MAC address change occurs.
Configuring Gratuitous ARP
By default, Arista switch interfaces reject gratuitous ARP request packets. The arp gratuitous accept command configures an L3 interface to accept the gratuitous ARP request packets sent from a different device in the network and add their mappings to the ARP table. Gratuitous ARP can be configured on Ethernet interfaces, VLANs/SVI, or L3 port channels, but has no effect on L2 interfaces.
switch (config)# interface ethernet 2/1
switch (config-if-Et2/1)# arp gratuitous acceptDisplaying ARP Entries
The show ip arp command displays ARP cache entries that map an IP address to a corresponding MAC address. The table displays addresses by their host names when the command includes the resolve argument.
- This command displays ARP cache entries that map MAC addresses to IPv4 addresses.
switch> show ip arp Address Age (min) Hardware Addr Interface 172.25.0.2 0 004c.6211.021e Vlan101, Port-Channel2 172.22.0.1 0 004c.6214.3699 Vlan1000, Port-Channel1 172.22.0.2 0 004c.6219.a0f3 Vlan1000, Port-Channel1 172.22.0.3 0 0045.4942.a32c Vlan1000, Ethernet33 172.22.0.5 0 f012.3118.c09d Vlan1000, Port-Channel1 172.22.0.6 0 00e1.d11a.a1eb Vlan1000, Ethernet5 172.22.0.7 0 004f.e320.cd23 Vlan1000, Ethernet6 172.22.0.8 0 0032.48da.f9d9 Vlan1000, Ethernet37 172.22.0.9 0 0018.910a.1fc5 Vlan1000, Ethernet29 172.22.0.11 0 0056.cbe9.8510 Vlan1000, Ethernet26 switch> - This command displays ARP cache entries that map MAC addresses to IPv4 addresses. Host names assigned to IP addresses are displayed in place of the address.
switch> show ip arp resolve Address Age (min) Hardware Addr Interface green-vl101.new 0 004c.6211.021e Vlan101, Port-Channel2 172.22.0.1 0 004c.6214.3699 Vlan1000, Port-Channel1 orange-vl1000.n 0 004c.6219.a0f3 Vlan1000, Port-Channel1 172.22.0.3 0 0045.4942.a32c Vlan1000, Ethernet33 purple.newcompa 0 f012.3118.c09d Vlan1000, Port-Channel1 pink.newcompany 0 00e1.d11a.a1eb Vlan1000, Ethernet5 yellow.newcompa 0 004f.e320.cd23 Vlan1000, Ethernet6 172.22.0.8 0 0032.48da.f9d9 Vlan1000, Ethernet37 royalblue.newco 0 0018.910a.1fc5 Vlan1000, Ethernet29 172.22.0.11 0 0056.cbe9.8510 Vlan1000, Ethernet26 switch>
ARP Inspection
Address Resolution Protocol (ARP) inspection command ip arp inspection vlan ip arp inspection vlan activates a security feature that protects the network from ARP spoofing. ARP requests and responses on untrusted interfaces are intercepted on specified VLANs, and intercepted packets are verified to have valid IP-MAC address bindings. All invalid ARP packets are dropped. On trusted interfaces, all incoming ARP packets are processed and forwarded without verification.
Enabling and Disabling ARP Inspection
By default, ARP inspection is disabled on all VLANs.
- This command enables ARP inspection on VLANs 1 through 150.
switch(config)# ip arp inspection vlan 1 - 150 switch(config)# - This command disables ARP inspection on VLANs 1 through 150.
switch(config)# no ip arp inspection vlan 1 - 150 switch(config)# - This command sets the ARP inspection default to VLANs 1 through 150.
switch(config)# default ip arp inspection vlan 1 - 150 switch(config)# - These commands enable ARP inspection on multiple VLANs 1 through 150 and 200 through 250.
switch(config)# ip arp inspection vlan 1-150,200-250 switch(config)#
Syslog for Invalid ARP Packets Dropped
When an invalid ARP packet is dropped, the following syslog message appears. The log severity level can be set higher if required.
%SECURITY-4-ARP_PACKET_DROPPED: Dropped ARP packet on interface Ethernet28/1 Vlan
2121 because invalid mac and ip binding. Received: 00:0a:00:bc:00:de/1.1.1.1.Displaying ARP Inspection States
The command show ip arp inspection vlan displays the configuration and operation state of ARP inspection. For a VLAN range specified by show ip arp inspection vlan only VLANs with ARP inspection enabled will be displayed. If no VLAN is specified, all VLANs with ARP inspection enabled are displayed. The operation state turns to Active when hardware is ready to trap ARP packets for inspection.
switch(config)# show ip arp inspection vlan 1 - 150
VLAN 1
----------
Configuration
: Enabled
Operation State : Active
VLAN 2
----------
Configuration
: Enabled
Operation State : Active
{...}
VLAN 150
----------
Configuration
: Enabled
Operation State : Active
switch(config)#Displaying ARP Inspection Statistics
The command show ip arp inspection statistics show ip arp inspection statistics displays the statistics of inspected ARP packets. For a VLAN specified by show ip arp inspection vlan only VLANs with ARP inspection enabled will be displayed. If no VLAN is specified, all VLANs with ARP inspection enabled are displayed.
The command clear arp inspection statistics clears ARP inspection.
- This command displays ARP inspection statistics for VLAN 1.
switch(config)# show ip arp inspection statistics vlan 2 Vlan : 2 ------------ ARP Req Forwarded = 20 ARP Res Forwarded = 20 ARP Req Dropped = 1 ARP Res Dropped = 1 Last invalid ARP: Time: 10:20:30 ( 5 minutes ago ) Reason: Bad IP/Mac match Received on: Ethernet 3/1 Packet: Source MAC: 00:01:00:01:00:01 Dest MAC: 00:02:00:02:00:02 ARP Type: Request ARP Sender MAC: 00:01:00:01:00:01 ARP Sender IP: 1.1.1 switch(config)# - This command displays ARP inspection statistics for ethernet interface 3/1.
switch(config)# show ip arp inspection statistics ethernet interface 3/1 Interface : 3/1 -------- ARP Req Forwarded = 10 ARP Res Forwarded = 10 ARP Req Dropped = 1 ARP Res Dropped = 1 Last invalid ARP: Time: 10:20:30 ( 5 minutes ago ) Reason: Bad IP/Mac match Received on: VLAN 10 Packet: Source MAC: 00:01:00:01:00:01 Dest MAC: 00:02:00:02:00:02 ARP Type: Request ARP Sender MAC: 00:01:00:01:00:01 ARP Sender IP: 1.1.1 switch(config)# - This command clears ARP inspection statistics.
switch(config)# clear arp inspection statistics switch(config)#
Configure Trust Interface
By default, all interfaces are untrusted. The command ip arp inspection trust configures the trust state of an interface.
- This command configures the trust state of an interface.
switch(config)# ip arp inspection trust switch(config)# - This command configures the trust state of an interface to untrusted.
switch(config)# no ip arp inspection trust switch(config)# - This command configures the trust state of an interface to its default (untrusted).
switch(config)# default ip arp inspection trust switch(config)#
Configure Rate Limit
When ARP inspection is enabled, ARP packets are trapped to the CPU. Two actions can be taken when the incoming ARP rate exceeds expectation. For notification purpose, the command ip arp inspection logging will enable logging of the incoming ARP packets. To prevent a denial-of-service attack, the command ip arp inspection limit will error-disable interfaces.
- This command enables logging of incoming ARP packets when its rate exceeds the configured value, and sets the rate to 2048 (which is the upper limit for the number of invalid ARP packets allowed per second), and sets the burst consecutive interval over which the interface is monitored for a high ARP rate to 15 seconds.
switch(config)# ip arp inspection logging rate 2048 burst interval 15 switch(config)# - This command configures the rate limit of incoming ARP packets to errdisable the interface when the incoming ARP rate exceeds the configured value, sets the rate to 512 (which is the upper limit for the number of invalid ARP packets allowed per second), and sets the burst consecutive interval over which the interface is monitored for a high ARP rate to 11 seconds.
switch(config)# ip arp inspection limit rate 512 burst interval 11 switch(config)# - This command displays verification of the interface specific configuration.
switch(config)# interface ethernet 3/1 switch(config)# ip arp inspection limit rate 20 burst interval 5 switch(config)# interface Ethernet 3/3 switch(config)# ip arp inspection trust switch(config)# show ip arp inspection interfaces Interface Trust State Rate (pps) Burst Interval ------------- ----------- ---------- -------------- Et3/1 Untrusted 20 5 Et3/3 Trusted None N/A switch(config)#
Configure Errdisable Caused by ARP Inspection
If the incoming ARP packet rate on an interface exceeds the configured rate limit in burst interval, the interface will be errdisabled (by default). If errdisabled, the interface will stay in this state until you intervene with the command errdisable detect cause arp-inspection (e.g., after you perform a shutdown or no shutdown of the interface) or it automatically recovers after a certain time period. The command errdisable recovery cause arp-inspection will enable auto recovery. The command errdisable recovery interval will enable sharing the auto recovery interval among all errdisable interfaces. (See the chapter Data Transfer Introduction for information on all errdisable commands.
- This command enables errdisable caused by an ARP inspection violation.
switch(config)# errdisable detect cause arp-inspection switch(config)# - This command disables errdisable caused by an ARP inspection violation.
switch(config)# no errdisable detect cause arp-inspection switch(config)# - This command enables auto recovery.
switch(config)# errdisable recovery cause arp-inspection switch(config)# - This command disables auto recovery.
switch(config)# no errdisable recovery cause arp-inspection switch(config)# - This command enables sharing the auto recovery interval of 10 seconds among all errdisable interfaces.
switch(config)# errdisable recovery interval 10 switch(config)# - This command disables sharing the auto recovery interval of 10 seconds among all errdisable interfaces.
switch(config)# no errdisable recovery interval 10 switch(config)# - This command displays the reason for a port entering the errdisable state.
switch(config)# show interfaces status errdisabled Port Name Status Reason ------------ ------------ ------------ --------------- Et3/2 errdisabled arp-inspection switch(config)#
Configure Static IP MAC Binding
The ARP inspection command ip source binding allows users to add static IP-MAC binding. If enabled, ARP inspection verifies incoming ARP packets based on the configured IP-MAC bindings. The static IP-MAC binding entry s only be configured on Layer 2 ports. By default, there is no binding entry on the system.
- This command configures static IP-MAC binding for IP address 127.0.0.1, MAC address 0001.0001.0001, vlan 1, and Ethernet interface slot 4 and port 1.
switch(config)# ip source binding 127.0.0.1 0001.0001.0001 vlan 1 interface ethernet 4/1 switch(config)# - This command configures static IP-MAC binding for IP address 127.0.0.1, MAC address 0001.0001.0001, vlan 1, and port-channel interface 20.
switch(config)# ip source binding 127.0.0.1 0001.0001.0001 vlan 1 interface port-channel 20 switch(config)# - This command displays the configured IP-MAC binding entries. Note that the Lease column is mainly used for displaying dynamic DHCP snooping binding entries. For static binding entries, lease time is shown as infinite.
switch(config)# show ip source binding 127.0.0.1 0001.0001.0001 static vlan 1 interface port-channel 20 MacAddress IpAddress Lease(sec) Type VLAN Interface --------------- ----------- ----------- ------ ----- -------------- 0001.0001.0001 127.0.0.1 infinite static 1 Port-Channel20 switch(config)#
IPv4 Routing
Internet Protocol version 4 (IPv4) is a communications protocol used for relaying network packets across a set of connected networks using the Internet Protocol suite. Routing transmits network layer data packets over connected independent subnets. Each subnet is assigned an IP address range and each device on the subnet is assigned an IP address from that range. The connected subnets have IP address ranges that do not overlap.
A router is a network device that connects multiple subnets. Routers forward inbound packets to the subnet whose address range includes the packets’ destination address. IPv4 and IPv6 are internet layer protocols that define packet-switched internetworking, including source-to-destination datagram transmission across multiple networks.
Enabling IPv4 Routing
When IPv4 routing is enabled, the switch attempts to deliver inbound packets to destination IPv4 addresses by forwarding them to interfaces or next hop addresses specified by the forwarding table.
The ip routing command enables IPv4 routing.
This command enables IP routing:
switch(config)# ip routing
switch(config)#Static and Default IPv4 Routes
Static routes are entered through the CLI and are typically used when dynamic protocols are unable to establish routes to a specified destination prefix. Static routes are also useful when dynamic routing protocols are not available or appropriate. Creating a static route associates a destination IP address with a local interface. The routing table refers to these routes as connected routes that are available for redistribution into routing domains defined by dynamic routing protocols.
The ip route command creates a static route. The destination is a network segment; the nexthop is either an IP address or a routable interface port. When multiple routes exist to a destination prefix, the route with the lowest administrative distance takes precedence.
By default, the administrative distance assigned to static routes is 1. Assigning a higher administrative distance to a static route configures it to be overridden by dynamic routing data. For example, a static route with a distance value of 200 is overridden by OSPF intra-area routes, which have a default distance of 110.
A route tag is a 32-bit number that is attached to a route. Route maps use tags to filter routes. Static routes have a default tag value of 0.
switch(config)# ip route 172.17.252.0/24 vlan 500
switch(config)#Creating Default IPv4 Routes
The default route denotes the packet forwarding rule that takes effect when no other route is configured for a specified IPv4 address. All packets with destinations that are not established in the routing table are sent to the destination specified by the default route.
The IPv4 destination prefix is 0.0.0.0/0 and the next-hop is the default gateway.
switch(config)# ip route 0.0.0.0/0 192.14.0.4
switch(config)#Dynamic IPv4 Routes
Dynamic routes are established by dynamic routing protocols. These protocols also maintain the routing table and modify routes to adjust for topology or traffic changes. Routing protocols assist the switch in communicating with other devices to exchange network information, maintaining routing tables, and establishing data paths.
The switch supports these dynamic IPv4 routing protocols:
Viewing IPv4 Routes and Network Components
Displaying the FIB and Routing Table
The show ip route command displays routing table entries that are in the forwarding information base (FIB), including static routes, routes to directly connected networks, and dynamically learned routes. Multiple equal-cost paths to the same prefix are displayed contiguously as a block, with the destination prefix displayed only on the first line.
The show running-config command displays configured commands not in the FIB. The show ip route summary command displays the number of routes, categorized by source, in the routing table.
- This command displays IP routes learned through BGP.
switch> show ip route bgp Codes: C - connected, S - static, K - kernel, O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1, E2 - OSPF external type 2, N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type2, B I - iBGP, B E - eBGP, R - RIP, A - Aggregate B E 170.44.48.0/23 [20/0] via 170.44.254.78 B E 170.44.50.0/23 [20/0] via 170.44.254.78 B E 170.44.52.0/23 [20/0] via 170.44.254.78 B E 170.44.54.0/23 [20/0] via 170.44.254.78 B E 170.44.254.112/30 [20/0] via 170.44.254.78 B E 170.53.0.34/32 [1/0] via 170.44.254.78 B I 170.53.0.35/32 [1/0] via 170.44.254.2 via 170.44.254.13 via 170.44.254.20 via 170.44.254.67 via 170.44.254.35 via 170.44.254.98 switch> - This command displays a summary of routing table contents.
switch> show ip route summary Route Source Number Of Routes ------------------------------------- connected 15 static 0 ospf 74 Intra-area: 32 Inter-area:33 External-1:0 External-2:9 NSSA External-1:0 NSSA External-2:0 bgp 7 External: 6 Internal: 1 internal 45 attached 18 aggregate 0 switch>
Displaying the IP Route Age
The show ip route age command displays the time when the route for the specified network was present in the routing table. It does not account for the changes in parameters like metric, next-hop etc.
switch> show ip route 172.17.0.0/20 age
Codes: C - connected, S - static, K - kernel,
O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1,
E2 - OSPF external type 2, N1 - OSPF NSSA external type 1,
N2 - OSPF NSSA external type2, B I - iBGP, B E - eBGP,
R - RIP, I - ISIS, A - Aggregate
B E 172.17.0.0/20 via 172.25.0.1, age 3d01h
switch>Displaying Gateways
A gateway is a router that provides access to another network. The gateway of last resort, also known as the default route, is the route that a packet uses when the route to its destination address is unknown. The IPv4 default route in is 0.0.0.0/0.
The show ip route gateway command displays IP addresses of all gateways (next hops) used by active routes.
switch> show ip route gateway
The following gateways are in use:
172.25.0.1 Vlan101
172.17.253.2 Vlan2000
172.17.254.2 Vlan2201
172.17.254.11 Vlan2302
172.17.254.13 Vlan2302
172.17.254.17 Vlan2303
172.17.254.20 Vlan2303
172.17.254.66 Vlan2418
172.17.254.67 Vlan2418
172.17.254.68 Vlan2768
172.17.254.29 Vlan3020
switch>Displaying Host Routes
The show ip route host command displays all host routes in the host forwarding table. Host routes are those whose destination prefix is the entire address (mask = 255.255.255.255 or prefix = /32). Each displayed host route is labeled with its purpose:
- F static routes from the FIB.
- R routes defined because the IP address is an interface address.
- B broadcast address.
- A routes to any neighboring host for which the switch has an ARP entry.
switch# show ip route host
R - receive B - broadcast F - FIB, A - attached
F 127.0.0.1 to cpu
B 172.17.252.0 to cpu
A 172.17.253.2 on Vlan2000
R 172.17.253.3 to cpu
A 172.17.253.10 on Vlan2000
R 172.17.254.1 to cpu
A 172.17.254.2 on Vlan2901
B 172.17.254.3 to cpu
B 172.17.254.8 to cpu
A 172.17.254.11 on Vlan2902
R 172.17.254.12 to cpu
F 172.26.0.28 via 172.17.254.20 on Vlan3003
via 172.17.254.67 on Vlan3008
via 172.17.254.98 on Vlan3492
via 172.17.254.86 on Vlan3884
via 172.17.253.2 on Vlan3000
F 172.26.0.29 via 172.25.0.1 on Vlan101
F 172.26.0.30 via 172.17.254.29 on Vlan3910
F 172.26.0.31 via 172.17.254.33 on Vlan3911
F 172.26.0.32 via 172.17.254.105 on Vlan3912
switch#IPv4 Multicast Counters
IPv4 multicast counters allow association of IPv4 multicast routes with a packet or byte counter.
Multicast Counters Hardware Overview
Platform Independent Requirements for Counters
- Enable/Disable counters
- Clear counters
- Show counters
- Configure counter mode for byte (default) or frame mode
Policer Counter Overview
The switch hardware has two policer banks, each with 4k entries and each entry has one 32 bit entry1, and one 32 bit entry2, which can be used as either packet counter or byte counter.
In the pipeline, each bank can have one policer index coming from upstream blocks, which means different features cannot update multiple policer entries in the same bank simultaneously. Therefore, different features cannot share entries in the same bank.
In switch hardware routing, each FFU/BST entry points to a corresponding RAM. A policer index is saved in the action ram, so when installing a multicast route into hardware, platform code will get a policer index and saved in the action field. If a policer index is unavailable, a counter is not added to the action field.
Switch hardware can have multiple features competing for the policer banks. It is desirable to have a platform command to reserve policer banks dedicated for a certain feature.
The following command reserves one or two policer banks to be used only by the named feature:
[no] platform fm6000 [nat|acl|qos|multicast] policer banks <1|2>
Available bank(s) are reserved for the feature. Otherwise the command takes effect at the next reboot or FocalPointV2 agent restart. This reservation guarantees the configured number of bank(s) for this feature. However, the feature can still possibly obtain the other policer bank if it needs more, and the other bank is available.
If a feature has a pending reservation request which is not fulfilled because of availability, and some other feature frees a bank, the bank will be allocated to the pending feature.
BGP Functions Supported for Arista Switches
- A single BGP instance
- Simultaneous internal (IBGP) and external (EBGP) peering
- Multiprotocol BGP
- BGP Confederations
Additional Requirements
- Reservation of policer banks
- Notification of policer bank availability when a policer entry is freed by other features
Multicast Counters iBGP and eBGP Configuration
Policer Usage
There are two types of counters – those created by wildcard creation and by specific creation. When a specific counter is required and the hardware runs out of policer entries, a wildcard counter is forced to give up its policer entry.
If the user configures a specific counter and the Starter Group (SG) already has a wildcard-created counter for it, then this counter is upgraded to a specific one, with no change in hardware policer index. If the user configures both a wildcard counter and specific counter for this SG, and subsequently deletes the specific counter, the counter for this SG is downgraded to a wildcard, with no change in hardware policer index. However, if another specific counter is pending for a hardware policer index, then this policer entry will be assigned to that counter due to its higher precedence.
Even if a counter is configured by the user, in order to conserve the use of hardware resources, do not allocate a policer entry until a real route (G, S) is programmed into the Frame Filtering and Forwarding Unit (FFU).
Configuring IPv4 Multicast Counters
Perform the following CLI steps to configure IPv4 multicast counters on the FM6000 platform:
Route Management
When routing is enabled, the switch discovers the best route to a packet’s destination address by exchanging routing information with other devices. IP routing is disabled by default.
Route Redistribution
Route redistribution is the advertisement, into a dynamic routing protocol’s routing domain, of connected (static) routes or routes established by other routing protocols. By default, the switch advertises only routes in a routing domain that are established by the protocol that defined the domain.
Route redistribution commands specify the scope of the redistribution action. By default, all routes from a specified protocol (or all static routes) are advertised into the routing domain. Commands can also filter routes by applying a route map, which defines the subset of routes to be advertised.
Equal Cost Multipath Routing (ECMP) and Load Sharing
Equal Cost Multi-Path (ECMP) is a routing strategy where traffic is forwarded over multiple paths that have equal routing metric values.
Configuring ECMP (IPv4)
All ECMP paths are assigned the same tag value; commands that change the tag value of a path also change the tag value of all paths in the ECMP route.
In a network topology using ECMP routing, hash polarization may result when all switches perform identical hash calculations. Hash polarization leads to uneven load distribution among the data paths. Hash polarization is avoided when switches use different hash seeds to perform hash calculations.
The ip load-sharing command provides the hash seed to an algorithm that the switch uses to distribute data streams among multiple equal-cost routes to a specified subnet.
switch(config)# ip load-sharing fm6000 20
switch(config)#Multicast Traffic Over ECMP
The switch attempts to spread outbound unicast and multicast traffic to all ECMP route paths equally. To disable the sending of multicast traffic over ECMP, use the multipath none command or the no version of the multipath deterministic command.
Resilient ECMP
Resilient ECMP is used for those prefixes where it is not desirable for routes to be rehashed due to link flap, typically where ECMP is being used for load balancing. Resilient ECMP configures a fixed number of next-hop entries in the hardware ECMP table for all the routes within a specified IP address prefix. Implementing fixed table entries for a specified next-hop address allows data flows that are hashed to a valid next-hop number to remain intact even when some of the next hops go down or come back online.
Resilient ECMP is enabled for all routes within a specified prefix using the ip hardware fib ecmp resilience command. The command specifies the maximum number of next-hop addresses that the hardware ECMP table can contain for the specified IP prefix, and configures a redundancy factor that facilitates the duplication of next-hop addresses in the table. The fixed table space for the address is the maximum number of next hops multiplied by the redundancy factor. When the table contains the maximum number of next-hop addresses, the redundancy factor specifies the number of times each address is listed in the table. When the table contains fewer than the maximum number of next-hop addresses, the table space entries are filled by additional duplication of the nexthop addresses.
Resilient ECMP is also available for IPv6 IP addresses.
switch(config)# ip hardware fib ecmp resilience 10.14.2.2/24 capacity 6 redundancy 4
switch(config)#Resilient Equal-Cost Multi-Path(RECMP) Deduping
Each route needs to allocate hardware table entries in the ASIC, which contains forwarding information for the route, such as what its next-hops are, what egress links each next-hop uses, etc. The network device uses these hardware table entries when making forwarding decisions for a packet that is meant for a certain route. These ECMP hardware tables are limited in size and can fill up quickly if there are a large number of these hardware table entries allocated. One option to ease the usage of these hardware tables is to force RECMP routes to share hardware table entries.
There is already an existing feature for RECMP routes to get them to point to the same hardware table entry if they share the same set of next hops and the ordering of the next-hops is the same. However, RECMP routes may end up sharing the same set of next-hops, but the next-hop ordering may be different between them, and therefore the routes end up occupying different hardware table entries in the ASIC. RECMP routing has a property wherein the current ordering of next-hops for a given route is influenced by its previous orderings. The ordering between the routes can differ because these routes may have had a different set of next hops at some previous time before they finally converged onto the same set of next-hops.
When the ECMP hardware resource usage crosses the high threshold, the deduping process begins, and it lasts until the ECMP hardware resource usage falls below the low threshold. Use the IP hardware fib next-hop resource optimization thresholds command to modify the thresholds.
Configuring Resilient ECMP Deduping
- The following command is used to disable all the hardware resource optimization features:
switch(config)# ip hardware fib next-hop resource optimization disabled - The following command is used to re-enable the all hardware resource optimization features after disabling them:
switch(config)# no ip hardware fib next-hop resource optimization disabled - The following command is used to configure the thresholds for starting and stopping the optimization:
switch(config)# ip hardware fib next-hop resource optimization thresholds low <20> high <80>Note:- The value specified for the threshold represents the percentage of resource utilization, and is an integer between 0 and 100.
- Setting the high threshold to 80 indicates that optimization starts when the resource utilization is above 80%. The default value of this threshold is 90.
- Setting the low threshold to 20 indicates that optimization stops when the resource utilization is below 20%. The default value of this threshold is 85.
Show Commands
- The show ip hardware fib summary command is used to display the statistics of this RECMP deduping:
Example
The last two lines of the output shows whether RECMP deduping is enabled, and what are the corresponding threshold values for starting and stopping the optimization process.switch# show ip hardware fib summary Fib summary ----------- Adjacency sharing: disabled BFD peer event: enabled Deletion Delay: 0 Protect default route: disabled PBR: supported URPF: supported ICMP unreachable: enabled Max Ale ECMP: 600 UCMP weight deviation: 0.0 Maximum number of routes: 0 Fib compression: disabled Resource optimization for adjacency programming: enabled Adjacency resource optimization thresholds: low 20, high 80 - The show hardware capacity command is used to display the utilization of the hardware resources. The example below shows the multi-level hierarchy ECMP resources:
switch# show hardware capacity Forwarding Resources Usage Table Feature Chip Used Used Free Committed Best Case High Entries (%) Entries Entries Max Watermark Entries ------- --------------- ------- -------- ------- -------- ------------ ------------ --------- ECMP 0 0% 4095 0 4095 0 ECMP Mpls 0 0% 4095 0 4095 0 ECMP Routing 0 0% 4095 0 4095 0 ECMP VXLANOverlay 0 0% 4095 0 4095 0 ECMP VXLANTunnel 0 0% 3891 0 3891 0
Limitations
- With RECMP deduping, optimization of a sub-optimal ECMP route requires releasing and reallocating hardware resources for the route. Therefore the process may increase overall convergence time for route programming. It may not be desirable to always start the optimization when the hardware resource is sufficient. The threshold value for starting the optimization should be adjusted based on the route scale of the network.
- The deduping of ECMP hardware resources may cause potential traffic flow disruption for traffic flows going over RECMP routes with changing hardware table entries. While the deduping process tries to minimize the amount of traffic flow disruption, it is still sometimes inevitable.
- RECMP hardware table entries can only be deduped to other RECMP hardware table entries that share the same set of nexthops. This puts a limit to the amount of RECMP hardware table entries that can be reduced to the number of RECMP hardware table entries with unique nexthop sets.
Unicast Reverse Path Forwarding (uRPF)
Unicast Reverse Path Forwarding (uRPF) verifies the accessibility of source IP addresses in packets that the switch forwards. The switch drops a packet when uRPF determines that the routing table does not contain an entry with a valid path to that packet’s source IP address.
IPv4 and IPv6 uRPF operate independently. uRPF is VRF aware. Commands that do not specify a VRF utilize the default instance. Multicast routing is not affected by uRPF.
- Strict mode: uRPF also verifies that a packet is received on the interface that its routing table entry will use for its return packet.
- Loose mode: uRPF validation does not consider the inbound packet’s ingress interface.
uRPF Operation
uRPF is configurable on interfaces. For packets arriving on a uRPF-enabled interfaces, the source IP address is verified by examining the source and destination addresses of unicast routing table entries.
uRPF requires a reconfigured routing table to support IP address verification. When uRPF is enabled for the first time, unicast routing is briefly disabled to facilitate the routing table reconfiguration. Multicast routing is not affected by the initial uRPF enabling.
A packet fails uRPF verification if the table does not contain an entry whose source or destination address matches the packet’s source IP address. In strict mode, the uRPF also fails when the matching entry’s outbound interface does not match the packet’s ingress interface.
- DHCP (Source is 0.0.0.0 – Destination is 255.255.255.255).
- IPv6 link local (FE80::/10).
- Multicast packets.
ECMP uRPF
When verifying ECMP routes, strict mode checks all possible paths to determine that a packet is received on the correct interface. Strict mode is supported for ECMP groups with a maximum of eight routing table entries. The switch reverts to loose mode for ECMP groups that exceed eight entries.
Default Routes
uRPF strict mode provides an allow-default option that accepts default routes. On interfaces that enable allow-default and a default route is defined, uRPF strict mode validates a packet even when the routing table does not contain an entry that matches the packet’s source IP address. When allow-default is not enabled, uRPF does not consider the default route when verifying an inbound packet.
Null Routes
NULL0 routes drop traffic destined to a specified prefix. When uRPF is enabled, traffic originating from null route prefixes is dropped in strict and loose modes.
uRPF Configuration
Unicast Reverse Path Forwarding (uRPF) is enabled for IPv4 packets ingressing the configuration mode interface through the ip verify command.
- This command enables uRPF loose mode on interface vlan 17.
switch(config)# interface vlan 17 switch(config-if-Vl17)# ip verify unicast source reachable-via any switch(config-if-Vl17)# show active interface Vlan17 ip verify unicast source reachable-via any switch(config-if-Vl17)# - This command enables uRPF strict mode on interface vlan 18.
switch(config)# interface vlan 18 switch(config-if-Vl18)# ip verify unicast source reachable-via rx switch(config-if-Vl18)# show active interface Vlan18 ip verify unicast source reachable-via rx switch(config-if-Vl18)#
Routing Tables / Virtual Routing and Forwarding (VRF)
An IP routing table is a data table that lists the routes to network destinations and metrics (distances) associated with those routes. A routing table is also known as a Routing Information Base (RIB).
- Management VRFs have routing disabled. They are typically used for management-related traffic.
- Dataplane VRFs have routing enabled. They support routing protocols and packet forwarding (hardware and software).
Dataplane VRFs are supported by Trident, FM6000, and Arad platform switches.
VRFs support unicast IPv4 and IPv6 traffic and multicast traffic. Loopback, SVI, and routed ports may be added to VRFs. Management ports may be added without any hardware forwarding.
To allow overlap in the sets of IP addresses used by different VRF instances, a Route Distinguisher (RD) may be prepended to each address. RDs are defined in RFC 4364.
Default VRF
The default VRF on Arista switches is called “default.” It is created automatically and cannot be renamed or configured. Some configuration options accept “default” as a VRF input.
User-Defined VRFs
A user-defined VRF is created with the vrf instance command. After its creation, a VRF may be assigned a Route Distinguisher (RD) with the rd (VRF configuration mode) command in the VRF submode of Router-BGP Configuration Mode.
- These commands create a VRF named purple, place the switch in BGP VRF configuration mode for that VRF, and specify a route distinguisher for the VRF identifying the administrator as AS 530 and assigning 12 as its local number.
switch(config)# vrf instance purple switch(config-vrf-purple)# router bgp 50 switch(config-router-bgp)# vrf purple switch(config-router-bgp-vrf-purple)# rd 530:12 switch(config-router-bgp-vrf-purple)# - To add interfaces to a user-defined VRF, enter configuration mode for the interface and use the vrf (Interface mode) command. Loopback, SVI, and routed ports can be added to a VRF.
These commands add vlan 20 to the VRF named purple.
switch(config)# interface vlan 20 switch(config-if-Vl20)# vrf purple switch(config-if-Vl20)# - The show vrf command shows information about user-defined VRFs on the switch.
This command displays information for the VRF named purple.
switch> show vrf purple Vrf RD Protocols State Interfaces ------- ---------- ---------- ----------- ------------ purple 64496:237 ipv4 no routing Vlan42, Vlan43 switch>
rd (VRF configuration mode)
The rd command issued in VRF Configuration Mode is a legacy command supported for backward compatibility. To configure a Route Distinguisher (RD) for a VRF, use the rd (VRF configuration mode) command.
Context-Active VRF
The context-active VRF specifies the default VRF that VRF-context aware commands use when displaying or refreshing routing table data.
The cli vrf command specifies the context-active VRF.
switch# cli vrf magenta
switch# show routing-context vrf
Current VRF routing-context is magentaThe show routing-context vrf command displays the context-active VRF.
switch> show routing-context vrf
Current VRF routing-context is magenta
switch>RIB Route Control
The Routing Information Base (RIB) is composed of the routing information learned by the routing protocols, including static routes. The Forwarding Information Base (FIB) is composed of the routes actually used to forward traffic through a router.
Forwarding Information Base (FIB) makes IP destination prefix-based switching decisions. The FIB is similar to a routing table or information base. It maintains the forwarding information for the winning routes from the RIB. When routing or topology changes occur in the network, the IP routing table information is updated, and those changes are reflected in the FIB.
Configuring FIB policy
The RIB calculates the best/winning routes to each destination and place these routes in the forwarding table. Based on the FIB policy configured the best routes are advertised.
For example, a FIB policy can be configured to deny the routes for FIB programming, however, it does not prevent these routes from being advertised by a routing protocol, or to be redistributed into another routing domain, or to be used for recursive resolution in the IP RIB. FIB policies control the size and content of the routing tables, and the best route to take to reach a destination.
The rib ipv4 | ipv6 fib policy command is used to enable FIB policy for a particular VRF under router general configuration mode.
- match interface
- match [ ip | ipv6 ] address prefix-list
- match [ ip | ipv6 ] resolved-next-hop prefix-list
- match isis level
- match metric
- match source-protocol
switch(config)# router general
switch(config-router-general)# vrf default
switch(config-router-general-vrf-default)# rib ipv4 fib policy map1Displaying FIB Information
Use the show rib route <ipv4|ipv6> fib policy exclude command to display the RIB information. The fib policy excluded option displays the RIB routes that have been excluded from being programmed into FIB, by FIB policy.
switch# show rib route ipv6 fib policy excluded
switch# show rib route ip bgp fib policy excluded
VRF name: default, VRF ID: 0xfe, Protocol: bgp
Codes: C - Connected, S - Static, P - Route Input
B - BGP, O - Ospf, O3 - Ospf3, I - Isis
> - Best Route, * - Unresolved Nexthop
L - Part of a recursive route resolution loop
>B 10.1.0.0/24 [200/0]
via 10.2.2.1 [115/20] type tunnel
via 10.3.5.1, Ethernet1
via 10.2.0.1 [115/20] type tunnel
via 10.3.4.1, Ethernet2
via 10.3.6.1, Ethernet3
>B 10.1.0.0/24 [200/0]
via 10.2.2.1 [115/20] type tunnel
via 10.3.5.1, Ethernet1
via 10.2.0.1 [115/20] type tunnel
via 10.3.4.1, Ethernet2
via 10.3.6.1, Ethernet3 Displaying RIB Route Information
Use the show rib route ip command to view the IPv4 RIB information.
This command displays IPv4 RIB static routes.
switch# show rib route ip static
VRF name: default, VRF ID: 0xfe, Protocol: static
Codes: C - Connected, S - Static, P - Route Input
B - BGP, O - Ospf, O3 - Ospf3, I - Isis
> - Best Route, * - Unresolved Nexthop
L - Part of a recursive route resolution loop
>S 10.80.0.0/12 [1/0]
via 172.30.149.129 [0/1]
via Management1, directly connected
>S 172.16.0.0/12 [1/0]
via 172.30.149.129 [0/1]
via Management1, directly connected
switch#IPv4 Route Scale
IPv4 routes are optimized to achieve route scale when route distribution has a large number of routes of one or two parameters, with each parameter consisting of prefix lengths 12, 16, 20, 24, 28, and 32. If two separate prefix lengths are configured (in any order), one of them must be the prefix length of 32.
Configuring IPv4 Route Scale
IPv4 route scale is enabled by the ip hardware fib optimize command for the configuration mode interface. The platform Layer 3 agent is restarted to ensure IPv4 routes are optimized with the agent SandL3Unicast terminate command for the configuration mode interface.
switch(config)# ip hardware fib optimize exact-match prefix-length 12 32
! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimizedOne of the two prefixes in this command is a prefix-length of 32, which is required in the instance where there are two prefixes. For this command to take effect, you must restart the platform Layer 3 agent.
switch(config)# agent SandL3Unicast terminate
SandL3Unicast was terminatedRestarting the platform Layer 3 agent results in deletion of all IPv4 routes, which are re-added to the hardware.
switch(config)# ip hardware fib optimize exact-match prefix-length 32 16
! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimizedOne of the two prefixes in this command is a prefix-length of 32, which is required in the instance where there are two prefixes. For this command to take effect, you must restart the platform Layer 3 agent.
- This configuration command restarts the platform Layer 3 agent to ensure IPv4 routes are optimized.
switch(config)#agent SandL3Unicast terminate SandL3Unicast was terminatedRestarting the platform Layer 3 agent results in deletion of all IPv4 routes, which are re-added to the hardware.
- This configuration command allows configuring prefix length 24.
switch(config)#ip hardware fib optimize exact-match prefix-length 24 ! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimized
In this instance, there is only one prefix-length, so a prefix-length of 32 is not required. For this command to take effect, you must restart the platform Layer 3 agent.
- This configuration command restarts the platform Layer 3 agent to ensure IPv4 routes are optimized.
switch(config)#agent SandL3Unicast terminate SandL3Unicast was terminatedRestarting the platform Layer 3 agent results in deletion of all IPv4 routes, which are re-added to the hardware.
-
This configuration command allows configuring prefix length 32.
switch(config)#ip hardware fib optimize exact-match prefix-length 32 ! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimizedFor this command to take effect, you must restart the platform Layer 3 agent.
- This configuration command restarts the platform Layer 3 agent to ensure IPv4 routes are optimized.
switch(config)# agent SandL3Unicast terminate SandL3Unicast was terminatedRestarting the platform Layer 3 agent results in deletion of all IPv4 routes, which are re-added to the hardware.
- This configuration command disables configuring prefix lengths 12 and 32.
switch(config)#no ip hardware fib optimize exact-match prefix-length 12 32 ! Please restart layer 3 forwarding agent to ensure IPv4 routes are not optimized
One of the two prefixes in this command is a prefix-length of 32, which is required in the instance where there are two prefixes. For this command to take effect, you must restart the platform Layer 3 agent.
- This configuration command restarts the platform Layer 3 agent to ensure IPv4 routes are not optimized.
switch(config)#agent SandL3Unicast terminate SandL3Unicast was terminatedRestarting the platform Layer 3 agent results in deletion of all IPv4 routes, which are re-added to the hardware.
- This configuration command attempts to configure prefix length 20 and 28 which triggers an error exception. One of the two prefixes in this command must be a prefix-length of 32, which is required in the instance where there are two prefixes.
switch(config)#ip hardware fib optimize exact-match prefix-length 20 28 % One of the prefix lengths must be 32
IPv4 routes of certain prefix lengths can be optimized for enhanced route scale. The followingcommand disable prefix optimization on the specified VRF(s) to provide more flexibility.
- This configuration command disables prefix optimization on the default VRF.
switch(config)# ip hardware fib optimize disable-vrf default ! Please restart layer 3 forwarding agent to ensure that the disable-vrf option change takes effect - This configuration command disables prefix optimization on VRFs named vrf1 andvrf2.
switch(config)# ip hardware fib optimize disable-vrf vrf1 vrf2 ! Please restart layer 3 forwarding agent to ensure that the disable-vrf option change takes effect - This configuration command restarts the platform Layer 3 agent to ensure disable-vrf configuration to take effect.
switch(config)# agent SandL3Unicast terminate SandL3Unicast was terminated
Starting from the eos Release 4.26.0F, /32 prefix length optimization command is supported in the R3 series.
- This configuration command enables prefix optimization on the default VRF.
switch(config)# ip hardware fib optimize vrf default prefix-length 32 ! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimized - This configuration command enables prefix optimization on VRFs named vrf1 and vrf2.
switch(config)# ip hardware fib optimize vrf vrf1 vrf2 prefix-length 32 ! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimized - This configuration command disables optimization on vrf1 and vrf2 optimization configured in above example.
switch(config)# no ip hardware fib optimize vrf vrf1 ! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimized
The platform trident forwarding-table partition flexible command enables ALPM Mode in Flexible UFT mode using a subset of resources, so ALPM and Exact Match can coexist. Prior to this release, ALPM could only be programmed in mode 4 where all the UFT resources were used and in flexible partition mode, configuring ALPM was not supported. This limits the number of IP routes that can be supported.
- This configuration command sets up the flexible partition.
switch(config)# platform trident forwarding-table partition flexible ? alpm Shared UFT bank entries for the ALPM table exact-match Shared UFT bank entries for the exact-match table l2-shared Shared UFT bank entries for the MAC table l3-shared Shared UFT bank entries for the host table - ALPM gives the route prefix in DEFIM (TCAM table for longest prefix matched (LPM) lookup) and ALPM tables.
switch(config)# platform trident forwarding-table partition flexible alpm ? 184320 Upto 180K LPM routes 368640 Upto 360K LPM routes
- DCS-7300X3: 180k and 360k are accepted.
- CCS-720XP: 144k and 96k are accepted.
- Other sizes are invalid.
IPv4 Routescale with 2-to-1 Compression
The IPv4 routescale with2-to-1 compression optimizes certain prefix lengths and enhances the route scale capabilities on 7500R, 7280R, 7500R2, and 7280R2 platforms. The compression is best suited to achieve route scale when route distribution has a large number of routes of one or two prefix lengths.
Configuring IPv4 Routescale 2-to-1 Compression
- In the following example we are configuring prefix length 20 and 24, expanding prefix length 19 and 23, and compressing prefix length 25.
switch(config)# ip hardware fib optimize prefix-length 20 24 expand 19 23 compress 25 ! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimized - In the following example we are configuring prefix length 20 and 23, expanding prefix length 19, compressing prefix length 24.
switch(config)# ip hardware fib optimize prefix-length 20 23 expand 19 compress 24 ! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimized - Optionally, you can also use the internet profile to configure the IPv4 route scale compression.
switch(config)# ip hardware fib optimize prefixes profile internet ! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimized
Configure a new TCAM profile for the compress configuration to work, and disable a few features in the new TCAM profile to make space for the flex-route feature in the hardware. Features like acl vlan ip and the mirror ip have to be disabled, if you need any of these features or any other features to be enabled with flex-route feature, contact the Arista team.
The internet profile works differently based on whether the flex-route feature is enabled in the TCAM profile or not. If the flex-route feature is enabled, the internet profile behaves like ip hardware fib optimize prefix-length 20 23 expand 19 22 compress 24. If the flex-route feature is disabled, the internet profile behaves as ip hardware fib optimize prefix-length 20 24 expand 19 23.
switch(config)# hardware tcam
switch(config-hw-tcam)# profile flex-route copy default
switch(config-hw-tcam-profile-flex-route)# feature flex-route copy system-feature-source-profile
switch(config-hw-tcam-profile-flex-route-feature-flex-route)# exit
switch(config-hw-tcam-profile-flex-route)# no feature acl vlan ip
switch(config-hw-tcam-profile-flex-route)# no feature mirror ip
switch(config-hw-tcam-profile-flex-route)# exit
Saving new profile 'flex-route'
switch(config-hw-tcam)# system profile flex-routeLimitations
- A maximum of two prefix lengths can be optimized directly at any point of time, of which only one can be a non-nibble aligned prefix length. Additional prefix lengths can be optimized using the expand or the compress options.
- A maximum of 1-to-4 way expansion and 2-to-1 way compression into any optimized prefix length is supported. Multiple expansion prefix lengths can be programmed at any time, however, there can be just one compression prefix length programmed at any given point in time.
- A maximum of 4096 next-hops can be reliably pointed to by the compressed prefixes using 2-to-1 way compression.
- The 2-to-1 compression cannot be enabled along with unicast RPF. When both features are enabled together, unicast RPF functionality may not be correct.
- The flex-route feature in TCAM profiles based only on the default profile, while disabling the acl vlan ip and the mirror ip features. Contact the Arista team if any other feature, that is not available in the default TCAM profile, is required to be supported along with the flex-route feature, including support for Mirror to GRE tunnel or ACLs on SVI.
- VXLAN is not supported with the compress option of this feature. There is no Syslog or a warning message when VXLAN is configured along with the 2-to-1 way compression feature.
Show Commands
The IPv4 route scale summary is displayed by the show platform arad ip route summary command for the configuration mode interface. Resources for all IPv4 route scale routes are displayed by the show platform arad ip route command for the configuration mode interface.
- This command shows hardware resource usage of IPv4 routes.
switch(config)# show platform arad ip route summary Total number of VRFs: 1 Total number of routes: 25 Total number of route-paths: 21 Total number of lem-routes: 4 - This command shows resources for all IPv4 routes in hardware. Routes that use the additional hardware resources appear with an asterisk (*).
switch(config)# show platform arad ip route Tunnel Type: M(mpls), G(gre) * - Routes in LEM ------------------------------------------------------------------------------------------------ | Routing Table | | |------------------------------------------------------------------------------------------------ |VRF| Destination | | | |Acl | |ECMP | FEC | Tunnel |ID | Subnet | Cmd | Destination |VID |Label| MAC / CPU Code |Index|Index|T Value ------------------------------------------------------------------------------------------------ |0 |0.0.0.0/8 |TRAP |CoppSystemL3DstMiss|0 | - |ArpTrap | - |1030 | - |0 |100.1.0.0/32 |TRAP |CoppSystemIpBcast |0 | - |BcastReceive | - |1032 | - |0 |100.1.0.0/32 |TRAP |CoppSystemIpUcast |0 | - |Receive | - |32766| - |0 |100.1.255.255/32|TRAP |CoppSystemIpBcast |0 | - |BcastReceive | - |1032 | - |0 |200.1.255.255/32|TRAP |CoppSystemIpBcast |0 | - |BcastReceive | - |1032 | - |0 |200.1.0.0/16 |TRAP |CoppSystemL3DstMiss|1007| - |ArpTrap | - |1029 | - |0 |0.0.0.0/0 |TRAP |CoppSystemL3LpmOver|0 | - |SlowReceive | - |1024 | - |0 |4.4.4.0/24* |ROUTE|Et10 |1007| - |00:01:00:02:00:03| - |1033 | - |0 |10.20.30.0/24* |ROUTE|Et9 |1006| - |00:01:00:02:00:03| - |1027 | -
IP Source Guard
IP Source Guard (IPSG) prevents IP spoofing attacks.
IP Source Guard (IPSG) filters inbound IP packets based on their source MAC and IP addresses. IPSG is supported in hardware. IPSG enabled on a Layer 2 port verifies IP packets received on this port. Packets are permitted if each packet source MAC and IP addresses match any of the user-configured IP-MAC binding entries on the receiving VLAN and port. Packets with no match are dropped immediately.
Configuring IPSG
IPSG is applicable only to Layer 2 ports, and is enabled by the ip verify source command for the configuration mode interface. When configured on Layer 3 ports, IPSG does not take effect until this interface is converted to Layer 2.
IPSG is supported on Layer 2 Port-Channels, not member ports. The IPSG configuration on port channels supersedes the configuration on the physical member ports. Therfore, source IP MAC binding entries should be configured on port channels using the ip source binding command. When configured on a port channel member port, IPSG does not take effect until this port is deleted from the port channel configuration.
- These configuration commands exclude VLAN IDs 1 through 3 from IPSG filtering. When enabled on a trunk port, IPSG filters the inbound IP packets on all allowed VLANs. IP packets received on VLANs 4 through 10 on ethernet 36 will be filtered by IPSG, while those received on VLANs 1 through 3 are permitted.
switch(config)# no ip verify source vlan 1-3 switch(config)# interface ethernet 36 switch(config-if-Et36)# switchport mode trunk switch(config-if-Et36)# switchport trunk allowed vlan 1-10 switch(config-if-Et36)# ip verify source switch(config-if-Et36)# - This configuration command configures source IP-MAC binding entries to IP address 10.1.1.1, MAC address 0000.aaaa.1111, VLAN ID 4094, and interface ethernet 36.
switch(config)# ip source binding 10.1.1.1 0000.aaaa.1111 vlan 4094 interface ethernet 36 switch(config)#
DHCP Server Show Commands
- DHCPv4 display example:
switch# show dhcp server ipv4 IPv4 DHCP Server is active Debug log is enabled DNS server(s): 10.2.2.2 DNS domain name: domainFoo Lease duration: 1 days 0 hours 0 minutes TFTP server: serverFoo (Option 66) 10.0.0.3 (Option 150) TFTP file: fileFoo Active Leases: 1 IPv4 DHCP interface status: Interface Status ------------------------------------------------- Ethernet1 Inactive (Could not determine VRF) Ethernet2 Inactive (Not in default VRF) Ethernet3 Inactive (Kernel interface not created yet) Ethernet4 Inactive (Not up) Ethernet5 Inactive (No IP address) Ethernet6 Active Vendor information: Vendor ID: default Sub-options Data ---------------- ---------------- 1 192.0.2.0, 192.0.2.1 Vendor ID: vendorFoo Sub-options Data ---------------- ----------- 2 192.0.2.2 3 “Foo” Subnet: 10.0.0.0/8 Subnet name: subnetFoo Range: 10.0.0.1 to 10.0.0.10 DNS server(s): 10.1.1.1 10.2.2.2 Lease duration: 3 days 3 hours 3 minutes Default gateway address: 10.0.0.3 TFTP server: subnetServerFoo (Option 66) 10.0.0.4 (Option 150) TFTP boot file: subnetFileFoo Active leases: 1 Reservations: MAC address: 1a1b.1c1d.1e1f IPv4 address: 10.0.0.1 MAC address: 2a2b.2c2d.2e2f IPv4 address: 10.0.0.2 - For DHCPv6, there are two additional fields in subnet information output, Direct field and the Relay field. These two fields specify if the DHCP Server is accepting broadcast or relayed messages.
The Direct field displays Active when the subnet matches the interface with DHCPv6 configured. This indicates the server is accepting broadcast messages.
The Direct field displays Inactive when there is another existing subnet already matching the interface, or when the subnet matches more than one DHCP configured interface.
Examples of outputs for the DHCPv6 show dhcp server command:
In this example, DHCPv6 is configured with subnet fe80::/10 while being enabled on Ethernet1 with address fe80::1/64 and on Ethernet3 with address fe80::2/64.switch# show dhcp server ipv6 IPv6 DHCP server is active Debug log is enabled DNS server(s): fe80::6 DNS domain name: testaristanetworks.com Lease duration: 1 days 3 hours 30 minutes Active leases: 0 IPv6 DHCP interface status: Interface Status --------------- ------ Ethernet1 Active Ethernet3 Active Subnet: fe80::/10 Subnet name: foo Range: fe80::1 to fe80::3 DNS server(s): fe80::4 fe80::5 Direct: Inactive (Multiple interfaces match this subnet: Ethernet1 Ethernet3) Relay: Active Active leases: 0 - This example illustrates when multiple subnets match an interface. In this example, DHCPv6 is configured with subnets fc00::/7 and fe80::/10 while being enabled on Ethernet1 with address fe80::1/10 and fc00::1/7.
switch#show dhcp server ipv6 IPv6 DHCP server is active DNS server(s): fc00::2 DNS domain name: testaristanetworks.com Lease duration: 1 days 3 hours 30 minutes Active leases: 0 IPv6 DHCP interface status: Interface Status --------------- ------ Ethernet1 Active Subnet: fc00::/7 Subnet name: foo Range: fc00::1 to fc00::5 DNS server(s): fc00::6 fc00::8 Direct: Inactive (This and other subnets match interface Ethernet1) Relay: Active Active leases: 0 Subnet: fe80::/10 Subnet name: bar Direct: Inactive (This and other subnets match interface Ethernet1) Relay: Active Active leases: 0 - When a subnet is disabled, the show dhcp server command displays the disable message with a reason. The number of active leases of the disabled subnets will be 0. In this example, there are overlapping subnets.
switch# show dhcp server IPv4 DHCP Server is active DNS server(s): 10.2.2.2 Lease duration: 1 days 0 hours 0 minutes Active Leases: 0 IPv4 DHCP interface status: Interface Status ------------------------------------------------- Ethernet1 Active Subnet: 10.0.0.0/24 (Subnet is disabled - overlapping subnet 10.0.0.0/8) Range: 10.0.0.1 to 10.0.0.10 DNS server(s): 10.3.3.3 10.4.4.4 Default gateway address: 10.0.0.4 Active leases: 0 Subnet: 10.0.0.0/8 (Subnet is disabled - overlapping subnet 10.0.0.0/24) DNS server(s): Default gateway address: 10.0.0.3 Active leases: 0 - In this example, the display output shows overlapping ranges.
switch# show dhcp server IPv4 DHCP Server is active DNS server(s): 10.2.2.2 Lease duration: 1 days 0 hours 0 minutes Active Leases: 0 IPv4 DHCP interface status: Interface Status ------------------------------------------------- Ethernet1 Active Subnet: 10.0.0.0/8 (Subnet is disabled - range 10.0.0.9-10.0.0.12 overlaps with an existing pool) Range: 10.0.0.1 to 10.0.0.10 Range: 10.0.0.9 to 10.0.0.12 DNS server(s): 10.3.3.3 10.4.4.4 Default gateway address: 10.0.0.4 Active leases: 0 - This example shows duplicate static IP address reservation.
Subnet: 10.0.0.0/8 (Subnet is disabled - ipv4-address 10.0.0.11 is reserved more than once) Subnet name: DNS server(s): Default gateway address: 10.0.0.3 Active leases: 0 Reservations: MAC address: 1a1b.1c1d.1e1f IPv4 address: 10.0.0.11 MAC address: 2a2b.2c2d.2e2f IPv4 address: 10.0.0.11 - Use the show dhcp server leases command to display detailed information about the IP addresses allocated by the DHCP Server (including the IP address, the expected end time for that address, the time when the address is handed out, and the equivalent MAC address).
switch# show dhcp server leases 10.0.0.10 End: 2019/06/20 17:44:34 UTC Last transaction: 2019/06/19 17:44:34 UTC MAC address: 5692.4c67.460a 2000:0:0:40::b End: 2019/06/20 18:06:33 UTC Last transaction: 2019/06/20 14:36:33 UTC MAC address: 165a.a86d.ffac
DHCP Server
The router with DHCP Server enabled acts as a server that allocates and delivers network addresses with desired configuration parameters to its hosts.
The DHCP server is based on ISC Kea.
The router with an DHCP Server enabled acts as a server that allocates and delivers network addresses with desired configuration parameters to its hosts.
DHCP Server support includes:
- Configurable on different interfaces: Routed, VLAN, LAG, Sub-interface, and LAG Sub-interface.
- Configurable lease time for allocated network addresses.
- Configurable DNS domain.
- Configurable DNS servers.
- Configurable subnets with parameters:
- Default gateway
- DNS servers
- Ranges
- Lease time
- Configurable TFTP server
- Configurable TFTP bootfile
- Configurable Vendor options with sub options
- Configurable sub option types include: IPv4 address, array of IPv4 addresses, and string
- TFTP bootfile now supports an URI
Additional features for DHCPv4 include a configurable static IP address for exclusive use by a given client, based on the client’s MAC address.
Example deployment:
DHCP Server on an aggregation switch, via VXLAN tunnels.
DHCP Server Overview
The dhcp server command configures an Ethernet interface on a switch with DHCP server enabled. Configure the following features on all platforms:
- Interfaces including Routed, VLANs, LAG, Sub-interface, and LAG Sub-interface
- Lease time for allocated network addresses
- DNS domains
- DNS servers
- Subnets with parameters:
- Default gateway
- DNS servers
- Ranges
- Lease time
- TFTP Server-Name (DHCP option 66 )
- TFTP server Bootfile-Name (DHCP option 67)
- List of TFTP servers (DHCP option 150)
- Vendor options with suboptions (DHCP option 43)
- Suboptions including IPv4 address, array of IPv4 addresses, and string.
- TFTP server Bootfile-Name (DHCP option 67) with support for an URI.
- Configurable static IP address for exclusive use by a given client, based on the client MAC address.
Minimal DHCP Server Configuration
The following displays a DHCP server enabled for IPv4 on Ethernet1 and IPv6 on Ethernet 2.
switch(config)#interface ethernet 1
switch(config-if-Et1)#dhcp server ipv4
switch(config)#interface ethernet 2
switch(config-if-Et2)#dhcp server ipv6The following file extract displays a minimal working configuration for DHCP IPv4.
interface Ethernet1
no switchport
dhcp server ipv4
ip address 192.0.2.1/24
dhcp server
subnet 192.0.2.0/24
range 192.0.2.100 192.0.2.199The following file extract displays a minimal working configuration for DHCP IPv6.
interface Vlan1409
dhcp server ipv6
ipv6 address 2001:db8:0:10::1/64/10
dhcp server
subnet 2001:db8:0:10::/64
range 2001:db8:0:10::1000 2001:db8:0:10::1fffConfiguring DHCP Servers
The DHCP server options configured globally per address family apply to all subnets. Access the following commands under the config-dhcp-server level.
The following command enters the DHCP server global configuration mode.
switch#configure
switch(config)#dhcp server
switch(config-dhcp-server)#Use the following command to disable the DHCP server.
switch(config-dhcp-server)#disabledUse the following commands to configure the DNS servers. Only two servers can be configured globally per address family.
switch(config-dhcp-server)#dns server ipv4 192.0.2.4 192.0.2.5
switch(config-dhcp-server)#dns server ipv6 2001:db8:0:10::53 2001:db8:0:10::5353The following commands configure the domain names for allocated IP addresses. For example, add a domain with the name podV4.example.com for DHCPv4 and a domain with the name podV6.example.com for DHCPv6.
switch(config-dhcp-server)#dns domain name ipv4 podV4.example.com
switch(config-dhcp-server)#dns domain name ipv6 podV6.example.comThe following commands configure lease time for the allocated IP addresses. For example, configure the lease time as one (1) day.
switch(config-dhcp-server)#lease time ipv4 1 days 0 hours 0 minutes
switch(config-dhcp-server)#lease time ipv6 1 days 0 hours 0 minutesThe following command configures the TFTP Server-Name. The server can be in the form of either an IPv4 address or a fully qualified domain name and only available in DHCPv4. For example, configure the TFTP server with the IPv4 address, 192.0.2.6.
switch(config-dhcp-server)#tftp server option 66 ipv4 192.0.2.6The following command configures the TFTP Servers.
switch(config-dhcp-server)#tftp server option 150 ipv4 192.0.2.6 192.0.2.7The following command configures the TFTP Server Bootfile-Name, only available in DHCPv4.
switch(config-dhcp-server)#tftp server file ipv4 bootfile.confThe following command configures Vendor specific option. To enter the Vendor option submode config-dhcp-vendor-ipv4 from config-dhcp-server config mode, specify a vendor class identifier, only available in DHCPv4. For example, Vendor option for clients with vendor class identifier vendorClassIDA.
switch(config-dhcp-server)#vendor-option ipv4 vendorClassIDAThe following command configures default. If you do not configure the default, the DHCP Server sends the configured Vendor option to clients requesting a Vendor option with a vendor class identifier that does not match any configured Vendor option.
switch(config-dhcp-server)#vendor-option ipv4 defaultThe following command configures suboptions for the Vendor. The configuration sends the resulting Vendor option in a hexadecimal format to the desired client. The output displays aVendor option with a suboption with IPv4 address 192.0.2.8, for clients with the vendor class identifier vendorClassIDA, resulting in Vendor option 1:4:c0:0:2:8.
Sub option number is 1
Length of the Data is 4
Data is c0:0:2:8
dhcp server
vendor-option ipv4 vendorClassIDA
sub-option 1 type ipv4-address data 192.0.2.8The following command configures the Vendor option with IPv4 addresses 192.0.2.8 and 192.0.2.9, for clients with the vendor class identifier vendorClassIDA, resulting in the Vendor option fe:8:c0:0:2:8:c0:0:2:9.
switch(config-dhcp-server)#vendor-option ipv4 vendorClassIDA sub-option 254 type array ipv4-address data 192.0.2.8 192.0.2.9The following command configures Vendor option with a string “vendor”, for all clients whose vendor class identifier does not match any configured Vendor option, resulting in Vendor option 1e:3:46:4f:4f..
switch(config-dhcp-server)#vendor-option ipv4 default sub-option 30 type string data "vendor"The following command sets up Vendor option holding two suboptions, suboption 1 holds the IPv4 address 192.0.2.8, and suboption 2 holds a string “vendor”, for all clients whose vendor class identifier does not match any configured Vendor option, resulting in Vendor option 1:4:c0:0:2:8:2:3:46:4f:4f.
switch(config-dhcp-server)#vendor-option ipv4 default sub-option 1 type ipv4-address data 192.0.2.8 sub-option 2 type string data “vendor"Configuring DHCP Server Subnets
DHCP Server settings can also be configured per subnet and overrides the DHCP Server global mode configurations. There can be multiple subnets configured, but they must not overlap. eos disables overlapping subnets.
The following command enters DHCP Server subnet mode under the IPv4 address family.
switch(config-dhcp-server)#subnet 192.0.2.0/32The following command enters DHCP Server subnet mode under IPv6 address family.
switch(config-dhcp-server)#subnet 2001:db8:0:10::/64The following command configures the name of the subnet. For example, name subnetV4 for DHCPv4 and subnetV6 for DHCPv6.
switch(config-dhcp-server)#subnet 192.0.2.0/24 name subnetV4
switch(config-dhcp-server)#subnet 2001:db8:0:10::/64 name subnetV6The following command configures range of IP addresses of the subnet. The range must be within the subnet mask, otherwise the subnet becomes disabled.
switch(config-dhcp-server)#subnet 192.0.2.0/24 range 192.0.2.100 192.0.2.199
switch(config-dhcp-server)#subnet 2001:db8:0:10::/64 range 2001:db8:0:10::1000 2001:db8:0:10::1fffThe following command configures the DNS servers for a subnet. Configure up to 2 servers per subnet.
switch(config-dhcp-server)#subnet 192.0.2.0/24 dns server 192.0.2.1 192.0.2.10
switch(config-dhcp-server)#subnet 2001:db8:0:10::/64 dns server 2001:db8:0:10::10 2001:db8:0:10::11switch(config-dhcp-server)#subnet 192.0.2.0/24 lease time ipv4 3 days 0 hours 0 minutes
switch(config-dhcp-server)#subnet fe80::/10 lease time ipv4 3 days 0 hours 0 minutesswitch(config-dhcp-server)#subnet 192.0.2.0/24 default-gateway 192.0.2.3switch(config-dhcp-server)#subnet 192.0.2.0/24 tftp server option 66 subnet-tftp.example.comswitch(config-dhcp-server)#subnet 192.0.2.0/24 tftp server option 150 192.0.2.6 192.0.2.7switch(config-dhcp-server)#subnet 192.0.2.0/24 tftp server file subnet-bootfile.confswitch(config-dhcp-server)#subnet 192.0.2.0/24
switch(config-dhcp-server-subnet-ipv4)#reservations mac-address 1a1b.1c1d.1e1f ipv4-address 192.0.2.201Displaying DHCP Information
Show DHCP Server Information
The following command displays the DHCP Server information.
switch# show dhcp server ipv4
IPv4 DHCP Server is active
Debug log is enabled
DNS server(s): 192.0.2.4 192.0.2.5
DNS domain name: podV4.example.com
Lease duration: 1 days 0 hours 0 minutes
TFTP server: 192.0.2.6 (Option 66)
192.0.2.6 192.0.2.7 (Option 150)
TFTP file: https://This email address is being protected from spambots. You need JavaScript enabled to view it.:123/example/one
Active Leases: 1
IPv4 DHCP interface status:
Interface Status
-------------------------------------------------
Ethernet1 Inactive (Could not determine VRF)
Ethernet2 Inactive (Not in default VRF)
Ethernet3 Inactive (Kernel interface not created yet)
Ethernet4 Inactive (Not up)
Ethernet5 Inactive (No IP address)
Ethernet6 Inactive (No Link Local address)
Ethernet7 Inactive (DHCP relay is configured for this interface)
Ethernet8 Inactive (DHCP relay is always on)
Ethernet9 Active
Vendor information:
Vendor ID: default
Sub-options Data
---------------- ----------------
1 192.0.2.0
2 “vendor”
Vendor ID: vendorClassIDA
Sub-options Data
---------------- --------------------
254 192.0.2.8, 192.0.2.9
Subnet: 192.0.2.0/24
Subnet name: subnetFooV4
Range: 192.0.2.100 to 192.0.2.199
DNS server(s): 192.0.2.1 192.0.2.10
Lease duration: 3 days 0 hours 0 minutes
Default gateway address: 192.0.2.3
TFTP server:
subnet-tftp.example.com (Option 66)
192.0.2.6 192.0.2.7 (Option 150)
TFTP boot file: subnet-bootfile.conf
Active leases: 1
Reservations:
MAC address: 1a1b.1c1d.1e1f
IPv4 address: 192.0.2.201
MAC address: 2a2b.2c2d.2e2f
IPv4 address: 192.0.2.150Displaying Disabled Subnets
When a subnet becomes disabled, the show dhcp server [ipv4|ipv6] output displays the disabled message under Disabled reason(s). None of the disabled subnets have active leases. Currently, the output displays only 2 disabled reasons.
switch# show dhcp server
IPv4 DHCP Server is active
DNS server(s): 10.2.2.2
Lease duration: 1 days 0 hours 0 minutes
Active Leases: 0
IPv4 DHCP interface status:
Interface Status
-------------------------------------------------
Ethernet1 Active
Subnet: 10.0.0.0/24 (Subnet is disabled)
Range: 10.0.0.1 to 10.0.0.10
DNS server(s): 10.3.3.3 10.4.4.4
Default gateway address: 10.0.0.4
Active leases: 0
Disabled reason(s):
Overlapping subnets: 10.0.0.0/8
Subnet: 10.0.0.0/8 (Subnet is disabled)
Range: 10.0.0.1 to 10.0.0.10
DNS server(s): 10.5.5.5
Default gateway address: 10.0.0.3
Active leases: 0
Disabled reason(s):
Overlapping subnets: 10.0.0.0/24
For Overlapping ranges:
switch# show dhcp server
IPv4 DHCP Server is active
DNS server(s): 10.2.2.2
Lease duration: 1 days 0 hours 0 minutes
Active Leases: 0
IPv4 DHCP interface status:
Interface Status
-------------------------------------------------
Ethernet1 Active
Subnet: 10.0.0.0/8 (Subnet is disabled)
Range: 10.0.0.1 to 10.0.0.10
Range: 10.0.0.9 to 10.0.0.12
DNS server(s): 10.3.3.3 10.4.4.4
Default gateway address: 10.0.0.4
Active leases: 0
Disabled reason(s):
Overlapping range: 10.0.0.9 to 10.0.0.12
E.g. Duplicate static IP address reservation:
Subnet: 10.0.0.0/8 (Subnet is disabled)
Subnet name:
Range: 10.0.0.1 to 10.0.0.10
DNS server(s): 10.5.5.5
Default gateway address: 10.0.0.3
Active leases: 0
Reservations:
MAC address: 1a1b.1c1d.1e1f
IPv4 address: 10.0.0.11
MAC address: 2a2b.2c2d.2e2f
IPv4 address: 10.0.0.11
Disabled reason(s):
Duplicate IPv4 address reservation: 10.0.0.11For DHCPv6, Direct and Relay indicates that the DHCP Server accepts broadcast and relayed messages.
switch# show dhcp server ipv6
IPv6 DHCP server is active
Debug log is enabled
DNS server(s): fe80::6
DNS domain name: aristanetworks.example.com
Lease duration: 1 days 3 hours 30 minutes
Active leases: 0
IPv6 DHCP interface status:
Interface Status
--------------- ------
Ethernet1 Active
Ethernet3 Active
Subnet: fe80::/10
Subnet name: foo
Range: fe80::1 to fe80::3
DNS server(s): fe80::4 fe80::5
Direct: Inactive (Multiple interfaces match this subnet: Ethernet1 Ethernet3)
Relay: Active
Active leases: 0For DHCPv6, a subnet may match only one interface and vice versa. Otherwise the subnet is disabled and no lease assigned for that subnet.
interface Ethernet1
no switchport
ipv6 address 2001:db8:0:10::1/64
dhcp server ipv6
interface Ethernet3
no switchport
ipv6 address 2001:db8:0:11::1/64
dhcp server ipv6
dhcp server
subnet 2001:db8::/56The following enables DHCPv6 on Ethernet1 (with address fc00::1/7 and fe80::1/10), and then configures subnets fc00::/7 and fe80::/64 for DHCPv6.
interface Ethernet1
no switchport
ipv6 address fc00::1/7
ipv6 address fe80::1/64 link-local
dhcp server ipv6
dhcp server
subnet fc00::/7
subnet fe80::/64
#show dhcp server ipv6
IPv6 DHCP server is active
DNS server(s): fc00::2
DNS domain name: aristanetworks.example.com
Lease duration: 1 days 3 hours 30 minutes
Active leases: 0
IPv6 DHCP interface status:
Interface Status
--------------- ------
Ethernet1 Active
Subnet: fc00::/7
Subnet name: foo
Range: fc00::1 to fc00::5
DNS server(s): fc00::6 fc00::8
Direct: Inactive (This and other subnets match interface Ethernet1)
Relay: Active
Active leases: 0
Subnet: fe80::/64
Subnet name: subnetBarV6
Direct: Inactive (This and other subnets match interface Ethernet1)
Relay: Active
Active leases: 0Leases
The following output displays the IP addresses allocated by the DHCP Server with the show dhcp server [ipv4|ipv6] leases command. It also displays the expected end time for the address, the time when the address is assigned, and the equivalent MAC address.
switch#show dhcp server leases
10.0.0.10
End: 2019/06/20 17:44:34 UTC
Last transaction: 2019/06/19 17:44:34 UTC
MAC address: 5692.4c67.460a
2000:0:0:40::b
End: 2019/06/20 18:06:33 UTC
Last transaction: 2019/06/20 14:36:33 UTC
MAC address: 165a.a86d.ffacDHCP Relay Global Configuration Mode
Configure the dhcp relay command in the global configuration mode. The command places the switch on DHCP Relay mode and allows the configuration of DHCP Relay on several interfaces with a single command. The configuration entered in the DHCP Relay global configuration mode can be overridden by equivalent interface specific commands.
Examples
The dhcp relay command places the switch in the DHCP Relay configuration mode.
switch(config)# dhcp relay
switch(config-dhcp-relay)#Specify the IP address of the default DHCP or DHCPv6 Server. Multiple IP addresses can be specified and DHCP requests forward to all specified helper addresses. Configure an ip helper-address IP_Address under each desired routing interface.
Use the following commands to forward DHCP broadcast packets received on interface Ethernet1 and Vlan2 to DHCP servers at 10.0.0.1, 10.0.0.2, and to hostname DefaultDHCPHostname:
switch(config)# interface ethernet1
switch(config-if-Et1)# no switchport
switch(config-if-Et1)# ip address 192.168.1.1/16
switch(config)# interface vlan2
switch(config-if-Et1)# ip address 172.16.1.1/16
switch(config)# dhcp relay
switch(config-dhcp-relay)# server 10.0.0.1
switch(config-dhcp-relay)# server 10.0.0.2
switch(config-dhcp-relay)# server DefaultDHCPHostnameswitch(config)# interface ethernet1
switch(config-if-Et1)# no switchport
switch(config-if-Et1)# ipv6 address fc00::1/10
switch(config)# dhcp relay
switch(config-dhcp-relay)# server fc00::3The configuration points a routed interface to the specified DHCP and DHCPv6 server, if the configuration meets following criteria:
- The default VRF contains the routed interface.
- The interface has an IP address configured.
- The configuration does not occur on a Management or a Loopback interface.
Use the following commands to remove the default DHCP or DHCPv6 Server.
switch(config)# dhcp relay
switch(config-dhcp-relay)# no server 10.0.0.1
switch(config-dhcp-relay)# no server 10.0.0.2
switch(config-dhcp-relay)# no server DefaultDHCPHostname
switch(config-dhcp-relay)# no server fc00::3To override the default DHCP Server on an interface, the parameter,ip helper-addressIP_Address, must be used.
switch(config)# interface ethernet 1
switch(config-if-Et1)# no switchport
switch(config-if-Et1)# ip address 192.168.1.1/16
switch(config)# interface vlan2
switch(config-if-Et1)# ip address 172.16.1.1/16
switch(config-if-Et1)# ip helper-address 10.0.0.3
switch(config)# dhcp relay
switch(config-dhcp-relay)# server 10.0.0.1
switch(config-dhcp-relay)# server 10.0.0.2
switch(config-dhcp-relay)# server DefaultDHCPHostnameTo override the default DHCPv6 Server on an interface, the parameter, ipv6 helper-address IPv6_Address> must be used.
switch(config)# interface ethernet 1
switch(config-if-Et1)# no switchport
switch(config-if-Et1)# ipv6 address fc00::1/10
switch(config)# interface vlan2
switch(config-if-Et1)# ipv6 address fc00::2/10
switch(config-if-Et1)# ipv6 helper-address fc00::4
switch(config)# dhcp relay
switch(config-dhcp-relay)# server fc00::3You can disable DHCP or DHCPv6 Relay functionality from a specific interface. This disables both DHCP Relay global and interface mode configurations.
switch(config)# interface vlan3
switch(config-if-Et1)# dhcp relay ipv4 disabledUse the following to disable DHCPv6 Relay functionality only.
switch(config)# interface Vvlan3
switch(config-if-Et1)# dhcp relay ipv6 disabledDisplaying DHCP Relay
The show ip dhcp relay command displays all the interfaces enabled with DHCP Relay and the server configured on these interfaces.
switch#show ip dhcp relay
DHCP Relay is active
DHCP Relay Option 82 is disabled
DHCPv6 Relay Link-layer Address Option (79) is disabled
DHCPv6 Relay Remote ID (Option 37) encoding format: MAC address:interface ID
DHCP Smart Relay is disabled
Default L3 interface DHCP servers:
DHCPv4 servers: 10.0.0.1
10.0.0.2
DefaultDHCPHostname
DHCPv6 servers: fc00::3
Interface: Ethernet1
DHCP Smart Relay is disabled
DHCPv6 all subnet relaying is disabled
Using default DHCPv4 servers
Using default DHCPv6 servers
Interface: Ethernet2
DHCP Smart Relay is disabled
DHCPv6 all subnet relaying is disabled
Using default DHCPv4 servers
DHCPv6 servers: fc00::4
Interface: Vlan2
DHCP Smart Relay is disabled
DHCPv6 all subnet relaying is disabled
DHCPv4 servers: 11.0.0.3
DHCPv6 servers: fc00::4
Interface: Vlan3
DHCP Smart Relay is disabled
DHCPv6 all subnet relaying is disabled
DHCPv4 Relay is disabled
DHCPv6 Relay is disabled DHCP Relay Across VRF
The eos DHCP relay agent supports forwarding of DHCP requests to DHCP servers located in a different VRF to the DHCP client interface VRF. In order to enable VRF support for the DHCP relay agent, Option 82 (DHCP Relay Agent Information Option) must first be enabled. The DHCP relay agent uses Option 82 to pass client specific information to the DHCP server.
-
VPN identifier: The VRF name for the ingress interface of the DHCP request, inserted as sub-option 151.
Table 1. VPN Identifier SubOpt Len ASCII VRF Identifier 151 7 V R F N A M E - Link selection: The subnet address of the interface that receives the DHCP request, inserted as sub-option 5. When the DHCP smart relay is enabled, the link selection is filled with the subnet of the active address. The relay agent will set the Gateway IP address (gIPaddr) to its own IP address so that DHCP messages can be routed over the network to the DHCP server.
Table 2. Link Selection SubOpt Len Subnet IP Address 5 4 A1 A2 A3 A4 - Server identifier override: The primary IP address of the interface that receives the DHCP request, inserted as sub-option 11. When the DHCP smart relay is enabled, the server identifier is filled with the active address (one of the primary or secondary addresses chosen by smart relay mechanism).
Table 3. Link Selection SubOpt Len Overriding Server Identifier Address 11 4 B1 B2 B3 B4 - VSS control suboption as suboption 152: The DHCP server will strip out this suboption when sending the response to the relay, indicating that the DHCP server used VPN information to allocate IP address.
Note: The DHCP server must be capable of handling VPN identifier information in option 82.
Direct communication between DHCP client and server may not be possible as they are in separate VRFs. The Server identifier override and Link Selection sub-options set the relay agent to act as the DHCP server, and enable all DHCP communication to flow through the relay agent.
The relay agent adds all the appropriate sub-options, and forwards all (including renew and release) request packets to the DHCP server. When the DHCP server response messages are received by the relay, Option 82 information is removed and the response is forwarded to the DHCP client in the client VRF.
Configuring DHCP Relay
The DHCP relay agent information option is inserted in DHCP messages relayed to the DHCP server. The ip helper-address command enables DHCP relay on an interface; and relays DHCP messages to the specified IPv4 address.
This command enables DHCP relay on the interface ethernet 1/2; and relays DHCP messages to the server at 1.1.1.1.
switch(config)# interface ethernet 1/2
switch(config-if-Et1/2)# ip helper-address 1.1.1.1
switch(config-if-Et1/2)#The commands provided in examples below will turn on the attachment of VRF-related tags in the relay agent information option. If both the DHCP client interface and server interface are on the same VRF (default or non-default), then no VRF-related DHCP relay agent information option is inserted.
- This command configures the DHCP relay to add option 82 information.
switch(config)# ip dhcp relay information option - These commands configures two new VRF instances and assign them Route Distinguishers (RDs).
switch(config)# vrf instance mtxxg-vrf switch(config-vrf-mtxxg-vrf)# router bgp 50 switch(config-router-bgp)# vrf mtxxg-vrf switch(config-router-bgp-vrf-mtxxg-vrf)# rd 5546:5546 switch(config)# vrf instance qchyh-vrf switch(config-vrf-qchyh-vrf)# router bgp 50 switch(config-router-bgp)# vrf qchyh-vrf switch(config-router-bgp-vrf-qchyh-vrf)# rd 218:218 - This command configures an interface connected to DHCP client in vrf mtxxg-vrf and assigns an IP address.
switch(config)# interface ethernet 9 switch(config-if-Et9)# no switchport - This command configures the DHCP client interface in VRF mtxxg-vrf.
switch(config-if-Et9)# vrf mtxxg-vrf switch(config-if-Et9)# ip address 10.10.0.1/16 - This command configures the server interface in VRF qchyh-vrf.
switch(config-if-Et11)# vrf qchyh-vrf switch(config-if-Et11)# ip address 10.40.0.1/16 - This command configures a helper address for a DHCP server in VRF qchyh-vrf.
switch(config-if-Et11)# ip helper-address 10.40.2.3 vrf qchyh-vrf
DHCP Relay Global Configuration Mode Show Command
Example
switch# show ip dhcp relay
DHCP Relay is active
DHCP Relay Option 82 is enabled
DHCP Smart Relay is disabled
Interface: Ethernet9
Option 82 Circuit ID: Ethernet9
DHCP Smart Relay is disabled
DHCP servers: 10.40.2.3
10.40.2.3:vrf=qchyh-vrfDHCP Relay in VXLAN EVPN
The ip dhcp relay information option (Global) command enables the configuration of the DHCP server to uniquely identify the origin of the request using a source-interface and the helper address. Configure the source interface with a routable address used by the DHCP server to uniquely identify the DHCP relay agent that forwarded the client request.
Configuring DHCP Relay in VXLAN EVPN (IPv4)
Use the following command to enable the DHCP relay information option (Option 82) required to specify a source interface.
switch (config)# ip dhcp relay information optionThe following configures a Loopback interface as the source interface.
switch (config)# interface Loopback1
switch (config-if-Lo1)# ip address 1.1.1.1/24Use the following commands to configure the Loopback interface as the specified source interface for the helper address.
switch (config)# interface vlan100
switch (config-if-Vl100)# ip helper-address 10.1.1.4 source-interface Loopback1Use the following commands to configure the Loopback interface when the DHCP server resides in a different VRF (red). The source interface must be configured in the DHCP server VRF for the command to take effect.
switch (config)# interface Loopback3
switch (config-if-Lo3)# vrf red
switch (config-if-Lo3)# ip address 1.1.1.1/24
switch (config)# interface vlan100
switch (config-if-Vl100)# ip helper-address 10.1.1.4 vrf red source-interface Loopback3The following command disables the use of source interface along with the helper address.
switch (config)# interface vlan100
switch (config-if-Vl100)# no ip helper-address 10.1.1.4 source-interface Loopback1Configuring DHCP Relay in VXLAN EVPN (IPv6)
Use the following commands to configure a local interface.
switch (config)# interface Loopback2
switch (config-if-Vl100)# ipv6 address 2001::10:20:30:1/128Use the following commands to configure the Loopback interface as the local interface for the helper address.
switch (config)# interface vlan200
switch (config-if-Vl200)# ipv6 dhcp relay destination 2002::10:20:30:2 local-interface Loopback2Use the following commands to configure the Loopback interface when the DHCP server is in a different VRF (red). The local interface must be configured in the DHCP server's VRF for the command to take effect.
switch (config)# interface Loopback4
switch (config-if-Lo4)# vrf red
switch (config-if-Lo4)# ipv6 address 2001::10:20:30:1/128
switch (config)# interface vlan200
switch (config-if-Vl200)# ipv6 dhcp relay destination 2002::10:20:30:2 vrf red local-interface Loopback4Use the following command to disable the use of local interface along with the helper address.
switch (config-if-Vl200)# no ipv6 dhcp relay destination 2002::10:20:30:2 local-interface Loopback4The following command displays the status of DHCP relay option (Option 82) and lists the configured DHCP servers.
switch# show ip dhcp relay
DHCP Relay is active
DHCP Relay Option 82 is enabled
DHCP Smart Relay is disabled
Interface: Vlan100
Option 82 Circuit ID: Vlan100
DHCP Smart Relay is disabled
DHCP servers: 10.1.1.4
Interface: Vlan200
Option 82 Circuit ID: Vlan100
DHCP Smart Relay is disabled
DHCP servers: 2002::10:20:30:2DHCP Snooping with Bridging
Configuring DHCP Snooping with Bridging
- Enable DHCP snooping feature using the ip dhcp snooping command.
switch# ip dhcp snooping - Enable the insertion of option-82 in DHCP request packets using the ip dhcp snooping information option command. By default, option-82 is not enabled and without this DHCP Snooping is not operational.
switch# ip dhcp snooping information option - Enable DHCP snooping on the corresponding VLANs using the ip dhcp snooping vlan command. By default, DHCP snooping is not enabled on any VLAN.
switch# ip dhcp snooping vlan - Set the circuit-id information that is sent in option-82. By default, Interface name and VLAN ID are sent. Remote circuit-id will always be the MAC address of the relay agent.
switch# ip dhcp snooping information option circuit-id type 2 format %h:%p Hostname and interface name %p:%v Interface name and VLAN ID - Enable bridging capabilities of DHCP snooping using the ip dhcp snooping bridging command. This command will enable DHCP snooping with or without DHCP relay configuration.
switch# ip dhcp snooping bridging
DHCP Snooping with Bridging Show Commands
switch# show ip dhcp snooping
DHCP Snooping is enabled
DHCP Snooping is operational
DHCP Snooping is configured on following VLANs:
650
DHCP Snooping bridging is operational on following VLANs:
650
Insertion of Option-82 is enabled
Circuit-id sub-option Type: 0
Circuit-id format: Interface name:Vlan ID
Remote-id: 00:1c:73:8d:eb:67 (Switch MAC)Troubleshooting
- Configure all the needed commands so that DHCP snooping is enabled and operational on all the VLANs.
- show ip dhcp snooping displays whether the DHCP snooping is operational or not.
- show ip dhcp snooping counters displays if snooped packets are getting dropped or not.
- show ip dhcp snooping counters debug displays the reason for packets getting dropped.
switch#show ip dhcp snooping counters debug Counter Requests Responses ----------------------------- ----------------- ----------------- Received 3 2 Forwarded 3 2 Dropped - Invalid VlanId 0 0 Dropped - Parse error 0 0 Dropped - Invalid Dhcp Optype 0 0 Dropped - Invalid Info Option 0 0 Dropped - Snooping disabled 0 0 - Check if the packets are hitting the TCAM rule.
switch#show platform trident tcam detail | grep -i dhcp DHCP Snooping uses 3 entries. … 655402 45 hits - DHCP client to relay trap-to-cpu
TCP MSS Clamping
TCP MSS clamping limits the value of the Maximum Segment Size (MSS) in the TCP header of TCP SYN packets transiting a specified Ethernet or tunnel interface. Setting the MSS ceiling can avoid IP fragmentation in tunnel scenarios by ensuring that the MSS is low enough to account for the extra overhead of GRE and tunnel outer IP headers. TCP MSS clamping can be used when connecting via GRE to cloud providers that require asymmetric routing.
When MSS clamping is configured on an interface, if the TCP MSS value in a SYN packet transiting that interface exceeds the configured ceiling limit it will be overwritten with the configured limit and the TCP checksum will be recomputed and updated.
TCP MSS clamping is handled by default in the software data path, but the process can be supported through hardware configuration to minimize possible packet loss and a reduction in the number of TCP sessions which the switch can establish per second.
Cautions
This feature should be used with caution. When the TCP MSS clamping feature is enabled by issuing the tcp mss ceiling command on any routed interface, all routed IPv4 TCP SYN packets (TCP packets with the “SYN” flag set) are sent by default to the CPU and switched through software, even on interfaces where no TCP MSS ceiling has been configured, as long as TCP MSS clamping is enabled. This limits the number of TCP sessions that can be established through the switch per second, and, because throughput for software forwarding is limited, this feature can also cause packet loss if the rate at which TCP SYN packets are sent to the CPU exceeds the limits configured in the control-plane policy map.
Packet loss and TCP session reductions can be minimized by enabling TCP MSS clamping in hardware, but only SYN packets in which MSS is the first TCP option are clamped in the hardware data path; other TCP SYN packets are still switched through software.
To disable MSS clamping, the MSS ceiling must be removed from every interface on which it has been configured by issuing the no tcp mss ceiling command on each configured interface.
Enabling TCP MSS Clamping
There is no global configuration to enable TCP MSS clamping. It is enabled as soon as an MSS ceiling is configured on at least one interface.
Disabling TCP MSS Clamping
To disable TCP MSS clamping, the MSS ceiling configuration must be removed from every interface by using the no or default form of the tcp mss ceiling command on every interface where a ceiling has been configured.
Configuring the TCP MSS Ceiling on an Interface
The TCP MSS ceiling limit is set on an interface using the tcp mss ceiling command. This also enables TCP MSS clamping on the switch as a whole.
- This command works only on egress.
- TCP MSS ceiling is supported on IPv4 unicast packets entering the switch; the configuration has no effect on GRE transit packets.
- The feature is supported only on IPv4 routed interfaces. It is not supported on L2 (switchport) interfaces or IPv6 routed interfaces.
- The feature is not supported for IPv6 packets even if they are going to be tunneled over an IPv4 GRE tunnel.
- The feature is not supported on VXLAN, loopback or management interfaces.
- The feature is only supported on IPv4 unicast packets entering the switch. The configuration has no effect on GRE transit packets or GRE decap, even if the egress interface has a TCP MSS ceiling configured.
Example
- These commands configure interface ethernet 5 as a routed port, then specify a maximum MSS ceiling value of 1458 bytes for TCP SYN packets exiting that port.
switch(config)# interface ethernet 5 switch(config-if-Et5)# no switchport switch(config-if-Et5)# tcp mss ceiling ipv4 1458 egress switch(config-if-Et5)# - These commands apply TCP MSS clamping at 1436 bytes in the egress direction for IPv6 packets:
switch(config)# interface ethernet 26 switch(config)# tcp mss ceiling ipv6 1436 egress - These commands apply TCP MSS clamping at 1476 bytes for IPv4 packets and 1436 bytes for IPv6 packets in egress direction:
switch(config)# interface ethernet 27 switch(config)# tcp mss ceiling ipv4 1476 ipv6 1436 egress
Verifying the TCP MSS Clamping
If TCP MSS ceiling is configured on an interface and if the command show cpu counters queue | nz is incrementing in CoppSystemL3Ttl1IpOptUcast field for Tcp packet with Syn flag, then TCP MSS clamping is being performed in Software.
switch# show cpu counters queue | nz
Fap0.1:
CoPP Class Queue Pkts Octets DropPkts DropOctets
Aggregate
------------------------------------------------------------------------------
CoppSystemL3Ttl1IpOptUcast TC0 1 82 0 0Configuring TCP MSS Clamping
Interface Configuration
You can specify the TCP MSS value under the interface configuration mode. The command syntax is shown below:
tcp mss ceiling [ipv4 | ipv6] 64-65515 egress
The keyword egress specifies that the MSS clamping is applied on packets transmitted out on the interface in egress direction.
switch(config)# interface ethernet 25
switch(config)#tcp mss ceiling ipv4 1436 egress switch(config)# interface ethernet 26
switch(config)# tcp mss ceiling ipv6 1436 egressswitch(config)# interface ethernet 27
switch(config)# tcp mss ceiling ipv4 1476 ipv6 1436 egressHardware TCP MSS Clamping Configuration
Hardware MSS clamping requires the system TCAM profile to have TCP MSS clamping enabled. You can achieve this by creating a user defined TCAM profile as described below. The User Defined PMF Profiles - TOI provides general guidelines on how to create and configure TCAM profiles.
The system TCAM profile must have the feature tcp-mss-ceiling ip in it in order to use hardware MSS clamping. This is applicable regardless of whether the TCAM profile is copied from an existing profile or created from scratch.
Step 1: Create the user defined TCAM profile
(config)# hardware tcam
(config-hw-tcam)# profile Pro1 copy Source1
(config-hw-tcam-profile-Pro1)# feature tcp-mss-ceiling ip copy system-feature-source-profile(config-hw-tcam-profile-Pro1-feature-Source1)# packet ipv4 forwarding routed(config-hw-tcam-profile-Pro1-feature-Source1)# key size limit 160(config-hw-tcam-profile-Pro1-feature-Source1)# exit
(config-hw-tcam-profile-Pro1)# no feature mirror ip
(config-hw-tcam-profile-Pro1)# no feature acl port macStep 2: Apply the user defined TCAM profile to the system.
(config-hw-tcam)# system profile redWhen the system TCAM profile is changed, it is expected that some agents will restart. Also it might be necessary to remove some unused features from the TCAM profile to ensure that the TCP MSS feature gets allocated a TCAM DB. For more information about configuring TCAM profiles, refer to User Defined PMF Profiles.
Backward Compatibility
The tunnel mss ceiling command which provides the same functionality is deprecated with the introduction of tcp mss ceiling command. The configuration option tunnel mss ceiling was available only on GRE tunnel interfaces, while tcp mss ceiling is supported on other routed IPv4 interfaces as well.
TCP MSS Clamping Limitations
- The TCP-MSS Clamping is not supported on L2 (switchport ) interfaces.
- The TCP-MSS Clamping is NOT supported on VXLAN, Loopback and Management interfaces.
- The TCP-MSS Clamping is supported only in the Egress direction.
- The TCP-MSS Clamping is only supported on unicast routed packets entering the switch. The configuration has no effect on GRE transit packets and GRE decap case, even if the Egress interface has TCP MSS ceiling configured.
Software TCP MSS Clamping Limitations
- Once the TCP-MSS Clamping is enabled, all routed TCP-SYN packets will be software switched, even on interfaces where there is no TCP-MSS ceiling configuration.
- TCP SYN packets could get dropped under high CPU usage conditions or due to DOS attack protection mechanisms such as PDP/CoPP. These factors could limit the TCP connection establishment rate, i.e new TCP sessions established per second through the switch.
Hardware MSS Clamping Limitations
- Hardware TCP-MSS clamping is not supported with host routes when the clamping is applied on a non-tunnel interface. This limitation does not apply to GRE tunnel interfaces.
- TCP SYN packets where TCP-MSS is not the first TCP option are trapped to CPU for MSS adjustment even in hardware MSS clamping mode.
- Hardware TCP-MSS clamping is not supported for IPv6 packets.
Configuring Hardware Support for TCP MSS Clamping
TCP MSS clamping can be supported in hardware, but some packets are still routed through the software data path, and an MSS ceiling value must be configured on each interface where clamping is to be applied.
Hardware support for clamping is accomplished through the use of a user-defined TCAM profile. The TCAM profile can be created from scratch or copied from an existing profile, but in either case it must include the tcp-mss-ceiling ip feature.
Guidelines
- When the system TCAM profile is changed, some agents will restart.
- To ensure that the TCP MSS feature is allocated a TCAM DB, it may be necessary to remove some unused features from the TCAM profile.
- Hardware TCP MSS clamping only works for TCP packets with MSS as the first TCP option. Other TCP SYN packets are still trapped to the CPU for clamping in software.
- Hardware TCP MSS clamping is not supported with host routes when the clamping is applied on a non-tunnel interface. This limitation does not apply to GRE tunnel interfaces.
- The maximum MSS ceiling limit with hardware MSS clamping is 32727 even though the CLI allows configuration of much larger values.
- For more information on the creation of user-defined TCAM profiles, see https://www.arista.com/en/support/toi/eos-4-20-5f/13977-user-defined-pmf-profile.
To configure hardware support for TCP MSS clamping, create a TCAM profile that includes the tcp mss ceiling feature, then apply it to the system.
Creating the TCAM Profile
A TCAM profile that supports TCP MSS clamping can be created from scratch, or the feature can be added to a copy of the default TCAM profile. When creating a profile from scratch, care must be taken to ensure that all needed TCAM features are included in the profile.
Modifying a Copy of the Default TCAM Profile
The following commands create a copy of the default TCAM profile, name it tcp-mss-clamping, and configure it to enable MSS clamping in hardware, then remove some unused features included in the default profile to ensure that there are sufficient TCAM resources for the clamping feature.
switch(config)# hardware tcam
switch(config-hw-tcam)# profile tcp-mss-clamping copy default
switch(config-hw-tcam-profile-tcp-mss-clampingl)# feature tcp-mss-ceiling ip copy
system-feature-source-profile
switch(config-hw-tcam-profile-tcp-mss-clamping-feature-tcp-mss-ceiling)# key
size limit 160
switch(config-hw-tcam-profile-tcp-mss-clamping-feature-tcp-mss-ceiling)# packet
ipv4 forwarding routed
switch(config-hw-tcam-profile-tcp-mss-clamping-feature-tcp-mss-ceiling)# exit
switch(config-hw-tcam-profile-tcp-mss-clamping)# no feature mirror ip
switch(config-hw-tcam-profile-tcp-mss-clamping)# no feature acl port mac
switch(config-hw-tcam-profile-tcp-mss-clampingl)# exit
switch(config-hw-tcam)# exit
switch(config)#Applying the TCAM Profile to the System
The following commands enter Hardware TCAM Configuration Mode and set the tcp-mss-clamping profile as the system profile.
switch(config)# hardware tcam
switch(config-hw-tcam)# system profile tcp-mss-clamping
switch(config-hw-tcam)#Verifying the TCAM Profile Configuration
The following command displays hardware TCAM profile information to verify that the user-defined TCAM profile has been applied correctly.
switch(config)# show hardware tcam profile
Configuration Status
FixedSystem tcp-mss-clamping tcp-mss-clamping
switch(config)#IPv4 GRE Tunneling
GRE tunneling supports the forwarding over IPv4 GRE tunnel interfaces. The GRE tunnel interfaces act as a logical interface that performs GRE encapsulation or decapsulation.
Configuring GRE Tunneling Interface
On a Local Arista Switch
switch(config)# ip routing
switch(config)# interface Tunnel 10
switch(config-if-Tu10)# tunnel mode gre
switch(config-if-Tu10)# ip address 192.168.1.1/24
switch(config-if-Tu10)# tunnel source 10.1.1.1
switch(config-if-Tu10)# tunnel destination 10.1.1.2
switch(config-if-Tu10)# tunnel path-mtu-discovery
switch(config-if-Tu10)# tunnel tos 10
switch(config-if-Tu10)# tunnel ttl 10On a Remote Arista Switch
switch(config)# ip routing
switch(config)# interface Tunnel 10
switch(config-if-Tu10)# tunnel mode gre
switch(config-if-Tu10)# ip address 192.168.1.2/24
switch(config-if-Tu10)# tunnel source 10.1.1.2
switch(config-if-Tu10)# tunnel destination 10.1.1.1
switch(config-if-Tu10)# tunnel path-mtu-discovery
switch(config-if-Tu10)# tunnel tos 10
switch(config-if-Tu10)# tunnel ttl 10 Alternative Configuration for Tunnel Source IPv4 Address
switch(config)# interface Loopback 10
switch(config-if-Lo10)# ip add 10.1.1.1/32
switch(config-if-Lo10)# exit
switch(config)# conf terminal
switch(config)# interface Tunnel 10
switch(config-if-Tu10)# tunnel source interface Loopback 10Configuration for Adding an IPv4 Route over the GRE Tunnel Interface
switch(config)# ip route 192.168.100.0/24 Tunnel 10Tunnel Mode
Tunnel Mode needs to be configured as gre, for GRE tunnel interface. Default value is tunnel mode gre.
IP Address
Configures the IP address for the GRE tunnel interface. The IP address can be used for routing over the GRE tunnel interface. The configured subnet is reachable over the GRE tunnel interface and the packets to the subnet are encapsulated in the GRE header.
Tunnel Source
Specifies the source IP address for the outer IPv4 encapsulation header for packets going over the GRE tunnel interface. The tunnel source IPv4 address should be a valid local IPv4 address configured on the Arista Switch. The tunnel source can also be specified as any routed interface on the Arista Switch. The routed interface’s IPv4 address is assigned as the tunnel source IPv4 address.
Tunnel Destination
Specifies the destination IPv4 address for the outer IPv4 encapsulation header for packets going over the GRE tunnel interface. The tunnel destination IPv4 should be reachable from the Arista Switch.
Tunnel Path Mtu Discovery
Specifies if the “Do not Fragment” flag needs to set in the outer IPv4 encapsulation header for packets going over the GRE tunnel interface.
Tunnel TOS
Specifies the Tunnel Type of Service (ToS) value to be assigned to the outer IPv4 encapsulation header for packets going over the GRE tunnel interface. Default TOS value of 0 will be assigned if tunnel TOS is not configured.
Tunnel TTL
Specifies the TTL value to the assigned to the outer IPv4 encapsulation header for packet going over the GRE tunnel interface. The TTL value is copied from the inner IPv4 header if tunnel TTL is not configured. The tunnel TTL configuration requires the tunnel Path MTU Discovery to be configured.
Displaying GRE tunnel Information
-
The following commands display the tunnel configuration.
switch# show interfaces Tunnel 10 Tunnel10 is up, line protocol is up (connected) Hardware is Tunnel, address is 0a01.0101.0800 Internet address is 192.168.1.1/24 Broadcast address is 255.255.255.255 Tunnel source 10.1.1.1, destination 10.1.1.2 Tunnel protocol/transport GRE/IP Key disabled, sequencing disabled Checksumming of packets disabled Tunnel TTL 10, Hardware forwarding enabled Tunnel TOS 10 Path MTU Discovery Tunnel transport MTU 1476 bytes Up 3 seconds -
switch# show gre tunnel static Name Index Source Destination Nexthop Interface -------- ------ -------- ------------ -------- ----------- Tunnel10 10 10.1.1.1 10.1.1.2 10.6.1.2 Ethernet6/1 switch# show tunnel fib static interface gre 10 Type 'Static Interface', index 10, forwarding Primary via 10.6.1.2, 'Ethernet6/1' GRE, destination 10.1.1.2, source 10.1.1.1, ttl 10, tos 0xa - Use the show platform fap tcam summary command to verify if the TCAM bank is allocated for GRE packet termination lookup.
switch# show platform fap tcam summary Tcam Allocation (Jericho0) Bank Used By Reserved By ---------- ------------ ----------- 0 dbGreTunnel - - Use the show ip route command to verify if the routes over tunnel is setup properly.
switch# show ip route VRF: default Codes: C - connected, S - static, K - kernel, O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1, E2 - OSPF external type 2, N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type2, B I - iBGP, B E - eBGP, R - RIP, I L1 - IS-IS level 1, I L2 - IS-IS level 2, O3 - OSPFv3, A B - BGP Aggregate, A O - OSPF Summary, NG - Nexthop Group Static Route, V - VXLAN Control Service, DH - DHCP client installed default route, M - Martian, DP - Dynamic Policy Route Gateway of last resort is not set C 192.168.1.0/24 is directly connected, Tunnel10, Static Interface GRE tunnel index 10, dst 10.1.1.2, src 10.1.1.1, TTL 10, TOS 10 S 192.168.100.0/24 is directly connected, Tunnel10, Static Interface GRE tunnel index 10, dst 10.1.1.2, src 10.1.1.1, TTL 10, TOS 10 - The following commands are used to verify the tunnel encapsulation programming.
switch# show platform fap eedb ip-tunnel gre interface Tunnel 10 ------------------------------------------------------------------------------- | Jericho0 | | GRE Tunnel Egress Encapsulation DB | |-----------------------------------------------------------------------------| | Bank/ | OutLIF | Next | VSI | Encap | TOS | TTL | Source | Destination| OamLIF| OutLIF | Drop| | Offset| | OutLIF | LSB | Mode | | | IP | IP | Set | Profile| | |-----------------------------------------------------------------------------| | 3/0 | 0x6000 | 0x4010 | 0 | 2 | 10 | 10 | 10.1.1.1 | 10.1.1.2 | No | 0 | No | switch# show platform fap eedb ip-tunnel ------------------------------------------------------------------------------- | Jericho0 | | IP Tunnel Egress Encapsulation DB | |-----------------------------------------------------------------------------| | Bank/ | OutLIF | Next | VSI | Encap| TOS | TTL | Src | Destination | OamLIF | OutLIF | Drop| | Offset| | OutLIF | LSB | Mode | Idx | Idx | Idx | IP | Set | Profile | | |-----------------------------------------------------------------------------| | 3/0 | 0x6000 | 0x4010 | 0 | 2 | 9 | 0 | 0 | 10.1.1.2 | No | 0 | No |
GRE Tunneling Support
GRE tunneling supports the forwarding over IPv4 GRE tunnel interfaces. The GRE tunnel interfaces act as a logical interface that performs GRE encapsulation or decapsulation. A maximum of 256 GRE-tunnel interfaces are supported.
switch(config)# ip routing
switch(config)# interface Tunnel 10
switch(config-if-Tu10)# tunnel mode gre
switch(config-if-Tu10)# ip address 192.168.1.1/24
switch(config-if-Tu10)# tunnel source 10.1.1.1
switch(config-if-Tu10)# tunnel destination 10.1.1.2
switch(config-if-Tu10)# tunnel path-mtu-discovery
switch(config-if-Tu10)# tunnel tos 10
switch(config-if-Tu10)# tunnel ttl 10switch(config)# ip routing
switch(config)# interface Tunnel 10
switch(config-if-Tu10)# tunnel mode gre
switch(config-if-Tu10)# ip address 192.168.1.2/24
switch(config-if-Tu10)# tunnel source 10.1.1.2
switch(config-if-Tu10)# tunnel destination 10.1.1.1underlayVrf
switch(config-if-Tu10)# tunnel path-mtu-discovery
switch(config-if-Tu10)# tunnel tos 10
switch(config-if-Tu10)# tunnel ttl 10switch(config)# ip route 192.168.100.0/24 Tunnel 10Use the show interfaces Tunnel command to display the interface tunnel.
switch(config)# show interfaces Tunnel 10
Tunnel10 is up, line protocol is up (connected)
Hardware is Tunnel, address is 0a01.0101.0800
Internet address is 192.168.1.1/24
Broadcast address is 255.255.255.255
Tunnel source 10.1.1.1, destination 10.1.1.2
Tunnel protocol/transport GRE/IP
Key disabled, sequencing disabled
Checksumming of packets disabled
Tunnel TTL 10, Hardware forwarding enabled
Tunnel TOS 10
Path MTU Discovery
Tunnel transport MTU 1476 bytes
Tunnel underlay VRF "underlayVrf"
Up 3 secondsUse the show gre tunnel static command to display a static interface tunnel.
switch(config)#show gre tunnel static
Name Index Source Destination Nexthop Interface
----------- ------- ----------- ------------- ---------- ----------
Tunnel10 10 10.1.1.1 10.1.1.2 10.6.1.2 Ethernet6/1Use the show tunnel fib static interface command to display a fib static interface tunnel.
switch(config)# show tunnel fib static interface gre 10
Type 'Static Interface', index 10, forwarding Primary
via 10.6.1.2, 'Ethernet6/1'
GRE, destination 10.1.1.2, source 10.1.1.1, ttl 10, tos 0xaTunnel Mode
Tunnel mode is GRE for a GRE-tunnel interface which is also the default tunnel mode.
IP address
Use this IP address for routing over the GRE-tunnel interface. The configuration subnet is reachable over the GRE-tunnel interface, and the packets to the subnet is encapsulated with the GRE header.
Tunnel Source
Specifies the source IP address for the encapsulating IPv4 header of a packet going over the GRE-tunnel interface. The tunnel source IPv4 address is a valid local IPv4 address configured on the Arista switch. It uses any route interface on the Arista switch. The routed interfaces IPv4 address assigns the tunnel source IPv4 address. Maximum of 16 unique tunnel source IPv4 addresses are supported across all GRE-tunnel interfaces.
The following is an example of an interface as a Tunnel source.
switch(config)# interface Loopback 10
switch(config-if-Lo10)# ip add 10.1.1.1/32
switch(config-if-Lo10)# exit
switch(config)# interface Tunnel 10
switch(config-if-Tu10)# tunnel source interface Loopback 10Tunnel Destination
Specifies the destination IPv4 address for the encapsulating IPv4 header of a packet going over the GRE-tunnel interface. The tunnel destination IPv4 is reachable from the Arista switch.
Tunnel Path MTU Discovery
The tunnel path Maximum Transmition Unit (MTU) Discovery specifies if the Don't Fragment (DF) flag needs to be set in the encapsulating IPv4 header of a packet going over the GRE-Tunnel interface. MTU configuration on the GRE-tunnel interface is used by control plane protocols and not enforced in hardware for packets forwarded in data-plane. The MTU change on the tunnel interface does not take effect until the tunnel interface is flapped.
Tunnel TOS
The Tunnel TOS specifies the TOS value to be set in the encapsulating IPv4 header of a packet going over the GRE-Tunnel interface. The default value of 0 is assigned if tunnel TOS is not configured. Maximum of seven unique tunnel TOS values are supported across all GRE-tunnel interfaces.
Tunnel TTL
The Tunnel TTL specifies the TTL value to be set in the encapsulating IPv4 header of a packet going over the GRE-tunnel interface. The TTL value is copied from the inner IPv4 header if tunnel TTL is not configured. The tunnel TTL configuration requires the tunnel path MTU discovery to be configured. Maximum of four unique tunnel TTL values are supported across all GRE-tunnel interfaces.
VRF Forwarding (Overlay VRF)
switch(config)# vrf instance overlayVrf
switch(config)# ip routing vrf overlayVrf
switch(config)# interface Tunnel 10
switch(config-if-Tu10)# vrf overlayVrfswitch(config)# ip route vrf overlayVrf 7.7.7.0/24 192.168.1.2VRF Forwarding (Underlay VRF)
switch(config)# vrf instance underlayVrf
switch(config)# interface Tunnel 10
switch(config-if-Tu10)# tunnel underlay vrf underlayVrfTCAM Bank Allocation
switch(config)# show platform fap tcam summary
Tcam Allocation (Jericho0)
Bank Used By Reserved By
---------- ------------------------- -----------
0 dbGreTunnel -PBR is not supported on GRE terminated packets.
Verifing Tunnel Routes
switch(config)# show ip route
VRF: default
Codes: C - connected, S - static, K - kernel,
O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1,
E2 - OSPF external type 2, N1 - OSPF NSSA external type 1,
N2 - OSPF NSSA external type2, B I - iBGP, B E - eBGP,
R - RIP, I L1 - IS-IS level 1, I L2 - IS-IS level 2,
O3 - OSPFv3, A B - BGP Aggregate, A O - OSPF Summary,
NG - Nexthop Group Static Route, V - VXLAN Control Service,
DH - DHCP client installed default route, M - Martian,
DP - Dynamic Policy Route
Gateway of last resort is not set
C 192.168.1.0/24 is directly connected, Tunnel10, Static Interface GRE-Tunnel index 10, dst 10.1.1.2, src 10.1.1.1, TTL 10, TOS 10
S 192.168.100.0/24 is directly connected, Tunnel10, Static Interface GRE-Tunnel index 10, dst 10.1.1.2, src 10.1.1.1, TTL 10, TOS 10Verifing Tunnel Encap
Use the show platform fap eedb ip-tunnel gre interface Tunnel command to check the tunnel encap programming on the GRE interface.
switch(config)# show platform fap eedb ip-tunnel gre interface Tunnel 10
------------------------------------------------------------------------------------------------------------------
| Jericho0 |
| GRE Tunnel Egress Encapsulation DB |
|------------------------------------------------------------------------------------------------------------------|
| Bank/ | OutLIF | Next | VSI | Encap | TOS | TTL | Source | Destination | OamLIF | OutLIF | Drop |
| Offset | | OutLIF | LSB | Mode | | | IP | IP | Set | Profile | |
|------------------------------------------------------------------------------------------------------------------|
| 3/0 | 0x6000 | 0x4010 | 0 | 2 | 10 | 10 | 10.1.1.1 | 10.1.1.2 | No | 0 | No |
Use the show platform fap eedb ip-tunnel command to check the tunnel encap programming on the IP-tunnel interface.
switch(config)# show platform fap eedb ip-tunnel
-----------------------------------------------------------------------------------------------------------
| Jericho0 |
| IP Tunnel Egress Encapsulation DB |
|-----------------------------------------------------------------------------------------------------------|
| Bank/ | OutLIF | Next | VSI | Encap | TOS | TTL | Src | Destination | OamLIF | OutLIF | Drop |
| Offset | | OutLIF | LSB | Mode | Idx | Idx | Idx | IP | Set | Profile | |
|-----------------------------------------------------------------------------------------------------------|
| 3/0 | 0x6000 | 0x4010 | 0 | 2 | 9 | 0 | 0 | 10.1.1.2 | No | 0 | No |Verifing Tunnel VRF
Use the show ip interface tunnel command to check the overlay VRF.
switch(config)# show ip interface tunnel 10
Tunnel10 is up, line protocol is up (connected)
Internet address is 192.168.1.1/24
Broadcast address is 255.255.255.255
IPv6 Interface Forwarding : None
Proxy-ARP is disabled
Local Proxy-ARP is disabled
Gratuitous ARP is ignored
IP MTU 1476 bytes
VPN Routing/Forwarding "overlayVrf"
switch(config)# show ip route vrf overlayVrf
VRF: overlayVrf
Codes: C - connected, S - static, K - kernel,
O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1,
E2 - OSPF external type 2, N1 - OSPF NSSA external type 1,
N2 - OSPF NSSA external type2, B I - iBGP, B E - eBGP,
R - RIP, I L1 - IS-IS level 1, I L2 - IS-IS level 2,
O3 - OSPFv3, A B - BGP Aggregate, A O - OSPF Summary,
NG - Nexthop Group Static Route, V - VXLAN Control Service,
DH - DHCP client installed default route, M - Martian,
DP - Dynamic Policy Route, L - VRF Leaked
Gateway of last resort is not set
C 1.1.1.0/24 is directly connected, Ethernet1
S 7.7.7.0/24 [1/0] via 192.168.1.2, Tunnel10, Static Interface GRE-Tunnel index 10, dst 10.1.1.2, src 10.1.1.1
C 192.168.1.0/24 is directly connected, Tunnel10, Static Interface GRE-Tunnel index 10, dst 10.1.1.2, src 10.1.1.1Tunnel underlay VRF Configuration
switch(config)# show interfaces Tunnel 10
Tunnel10 is up, line protocol is up (connected)
Hardware is Tunnel, address is 0a01.0101.0800
Internet address is 192.168.1.1/24
Broadcast address is 255.255.255.255
Tunnel source 10.1.1.1, destination 10.1.1.2
Tunnel protocol/transport GRE/IP
Key disabled, sequencing disabled
Checksumming of packets disabled
Tunnel TTL 10, Hardware forwarding enabled
Tunnel TOS 10
Path MTU Discovery
Tunnel transport MTU 1476 bytes
Tunnel underlay VRF "underlayVrf"
Up 3 seconds
Use the show ip route vrf underlayVrf command to check the IP route VFR underlayVRF.
switch(config)# show ip route vrf underlayVrf
VRF: underlayVrf
Codes: C - connected, S - static, K - kernel,
O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1,
E2 - OSPF external type 2, N1 - OSPF NSSA external type 1,
N2 - OSPF NSSA external type2, B - BGP, B I - iBGP, B E - eBGP,
R - RIP, I L1 - IS-IS level 1, I L2 - IS-IS level 2,
O3 - OSPFv3, A B - BGP Aggregate, A O - OSPF Summary,
NG - Nexthop Group Static Route, V - VXLAN Control Service,
DH - DHCP client installed default route, M - Martian,
DP - Dynamic Policy Route, L - VRF Leaked,
Gateway of last resort is not set
C 10.1.1.0/24 is directly connected, Ethernet1BfRuntime to Use Non-default VRFs
Use the following to configure the VRF for the BfRuntime connection for the management interface on the switches that support it. The management interface may be configured on a different VRF from the default one.
Configuring BfRuntime to Use Non-default VRFs
(config)# platform barefoot bfrt vrf <VRF name>If left unconfigured, the default VRF is used for the IP and port for the the BfRuntime server.
(config)# vrf instance management
(config-vrf-management)# exit
(config)# platform barefoot bfrt 0.0.0.0 50052
(config)# platform barefoot bfrt vrf <VRF name>
(config)# int management1
(config-if-Ma1)# vrf managementDisplaying BfRuntime Configuration
(switch)# show platform barefoot bfrt
Namespace: management
FixedSystem:0.0.0.0:50052IPv4 Commands
IP Routing and Address Commands
- agent SandL3Unicast terminate
- clear arp inspection statistics
- compress
- ip arp inspection limit
- ip arp inspection logging
- ip arp inspection trust
- ip arp inspection vlan
- ip hardware fib ecmp resilience
- ip hardware fib optimize
- ip hardware fib next-hop resource optimization
- ip icmp redirect
- ip load-sharing
- ip route
- ip routing
- ip source binding
- ip verify
- ip verify source
- ipv4 routable 240.0.0.0/4
- rib fib policy
- show dhcp server
- show hardware capacity
- show ip
- show ip arp inspection vlan
- show ip arp inspection statistics
- show ip hardware fib summary
- show ip interface
- show ip interface brief
- show ip route
- show ip route age
- show ip route gateway
- show ip route host
- show ip route match tag
- show ip route summary
- show ip verify source
- show platform arad ip route
- show platform arad ip route summary
- show rib route ip
- show rib route fib policy excluded
- show rib route summary
- show routing-context vrf
- show vrf
- tcp mss ceiling
IPv4 DHCP Relay Commands
DHCP Server Configuration Commands
IPv4 DHCP Snooping Commands
IPv4 Multicast Counters Commands
ARP Table Commands
VRF Commands
Trident Forwarding Table Commands
IPv4 GRE Tunneling Commands
agent SandL3Unicast terminate
The agent SandL3Unicast terminate command restarts the platform Layer 3 agent to ensure IPv4 routes are optimized.
Command Mode
Global Configuration
Command Syntax
agent SandL3Unicast terminate
- ip hardware fib optimize enables IPv4 route scale.
- show platform arad ip route shows resources for all IPv4 routes in hardware. Routes that use the additional hardware resources will appear with an asterisk.
- show platform arad ip route summary shows hardware resource usage of IPv4 routes.
switch(config)# agent SandL3Unicast terminate
SandL3Unicast was terminatedRestarting the platform Layer 3 agent results in deletion of all IPv4 routes, which are re-added to the hardware.
arp
The arp command adds a static entry to an Address Resolution Protocol (ARP) cache. The switch uses ARP cache entries to correlate 32-bit IP addresses to 48-bit hardware addresses.
The no arp and default arp commands remove the ARP cache entry with the specified IP address. When multiple VRFs contain ARP cache entries for identical IP addresses, each entry can only be removed individually.
Command Mode
Global Configuration
Command Syntax
arp [VRF_INSTANCE] ipv4_addr mac_addr arpa
no arp [VRF_INSTANCE] ipv4_addr
default arp [VRF_INSTANCE] ipv4_addr
-
VRF_INSTANCE Specifies the VRF instance being modified.
- no parameter Changes are made to the default VRF.
- vrf vrf_name Changes are made to the specified user-defined VRF.
- ipv4_addr IPv4 address of ARP entry.
- mac_addr Local data-link (hardware) address (48-bit dotted hex notation – H.H.H).
- This command adds a static entry to the ARP cache in the default VRF.
switch(config)# arp 172.22.30.52 0025.900e.c63c arpa switch(config)# - This command adds the same static entry to the ARP cache in the VRF named purple.
switch(config)# arp vrf purple 172.22.30.52 0025.900e.c63c arpa switch(config)#
arp aging timeout
The arp aging timeout command specifies the duration of dynamic address entries in the Address Resolution Protocol (ARP) cache for addresses learned through the configuration mode interface. The default duration is 14400 seconds (four hours).
The arp aging timeout and default arp aging timeout commands restores the default ARP aging timeout for addresses learned on the configuration mode interface by deleting the corresponding arp aging timeout command from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Loopback Configuration
Interface-Management Configuration
Interface-Port-channel Configuration
Interface-VLAN Configuration
Command Syntax
arp aging timeout arp_time
no arp aging timeout
default arp aging timeout
Parameters
arp_time ARP aging timeout period (seconds). Values range from 60 to 65535. Default value is 14400.
switch(config)# interface vlan 200
switch(config-if-Vl200)# arp aging timeout 7200
switch(config-if-Vl200)# show active
interface Vlan200
arp aging timeout 7200
switch(config-if-Vl200)#arp cache persistent
The arp cache persistent command restores the dynamic entries in the Address Resolution Protocol (ARP) cache after reboot.
The no arp cache persistent and default arp cache persistent commands remove the ARP cache persistent configuration from the running-config.
Command Mode
Global Configuration
Command Syntax
arp cache persistent
no arp cache persistent
default arp cache persistent
switch(config)# arp cache persistent
switch(config)#arp gratuitous accept
The arp gratuitous accept command configures the configuration mode interface to accept gratuitous ARP request packets received on that interface. Accepted gratuitous ARP requests are then learned by the ARP table.
The no and default forms of the command prevent the interface from accepting gratuitous ARP requests. Configuring gratuitous ARP acceptance on an L2 interface has no effect.
Command Mode
Interface-Ethernet Configuration
Interface-VLAN Configuration
Interface Port-channel Configuration
Command Syntax
arp gratuitous accept
no arp gratuitous accept
default arp gratuitous accept
switch(config)# interface ethernet 2/1
switch(config-if-Et2/1)# arp gratuitous accept
switch(config-if-Et2/1)#arp proxy max-delay
The arp proxy max-delay command enables delayingproxy ARP requests on the configuration mode interface. Proxy ARP is disabled by default. When proxy ARP is enabled, the switch responds to all ARP requests, including gratuitous ARP requests, with target IP addresses that match a route in the routing table. When a switch receives a proxy ARP request, eos performs a check to send the response immediately or delay the response based on the configured maximum delay in milliseconds (ms).
Command Mode
Configuration mode
Command Syntax
arp proxy max-delay milliseconds
Parameters
- arp proxy max-delay milliseconds - Configure the maximum delay before returning a proxy ARP response in milliseconds. Use a range between 0 and 1000ms with a default value of 800ms.
Example
This command sets a delay of 500ms before returning a response to a proxy ARP request.
switch(config)#arp proxy max-delay 500msclear arp inspection statistics
The clear arp inspection statistics command clears ARP inspection statistics.
Command Mode
EXEC
Command Syntax
clear arp inspection statistics
switch(config)# clear arp inspection statistics
switch(config)#clear arp
The clear arp command removes the specified dynamic ARP entry for the specified IP address from the Address Resolution Protocol (ARP) table.
Command Mode
Privileged EXEC
Command Syntax
- VRF_INSTANCE Specifies the VRF instance for which arp data is removed.
- no parameter Specifies the context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
-
ipv4_addr IPv4 address of dynamic ARP entry.
switch# show arp
Address Age (min) Hardware Addr Interface
172.22.30.1 0 001c.730b.1d15 Management1
172.22.30.52 0 0025.900e.c468 Management1
172.22.30.53 0 0025.900e.c63c Management1
172.22.30.133 0 001c.7304.3906 Management1
switch# clear arp 172.22.30.52
switch# show arp
Address Age (min) Hardware Addr Interface
172.22.30.1 0 001c.730b.1d15 Management1
172.22.30.53 0 0025.900e.c63c Management1
172.22.30.133 0 001c.7304.3906 Management1
switch#clear arp-cache
The clear arp-cache command refreshes dynamic entries in the Address Resolution Protocol (ARP) cache. Refreshing the ARP cache updates current ARP table entries and removes expired ARP entries not yet deleted by an internal, timer-driven process.
The command, without arguments, refreshes ARP cache entries for all enabled interfaces. With arguments, the command refreshes cache entries for the specified interface. Executing clear arp-cache for all interfaces can result in extremely high CPU usage while the tables are resolving.
Command Mode
Privileged EXEC
Command Syntax
clear arp-cache [VRF_INSTANCE][INTERFACE_NAME]
- VRF_INSTANCE Specifies the VRF instance for which arp data is refreshed.
- no parameter Specifies the context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
- INTERFACE_NAME Interface upon which ARP cache entries are refreshed. Options include:
- no parameter All ARP cache entries.
- interface ethernet e_num ARP cache entries of specified Ethernet interface.
- interface loopback l_num ARP cache entries of specified loopback interface.
- interface management m_num ARP cache entries of specified management interface.
- interface port-channel p_num ARP cache entries of specified port-channel Interface.
- interface vlan v_num ARP cache entries of specified VLAN interface.
- interface VXLAN vx_num VXLAN interface specified by vx_num.
Related Commands
The cli vrf command specifies the context-active VRF.
switch# show arp
Address Age (min) Hardware Addr Interface
172.22.30.1 0 001c.730b.1d15 Management1
172.22.30.118 0 001c.7301.6015 Management1
switch# clear arp-cache
switch# show arp
Address Age (min) Hardware Addr Interface
172.22.30.1 0 001c.730b.1d15 Management1
switch#clear ip dhcp relay counters
The clear ip dhcp relay counters command resets the DHCP relay counters. The configuration mode determines which counters are reset:
Interface configuration: command clears the counter for the configuration mode interface.
Command Mode
Privileged EXEC
Command Syntax
clear ip dhcp relay counters [INTERFACE_NAME]
Parameters
- no parameter Clears counters for the switch and for all interfaces.
- interface ethernet e_num Clears counters for the specified Ethernet interface.
- interface loopback l_num Clears counters for the specified loopback interface.
- interface port-channel p_num Clears counters for the specified port-channel Interface.
- interface vlan v_num Clears counters for the specified VLAN interface.
- These commands clear the DHCP relay counters for vlan 1045 and shows the counters before and after the clear command.
switch# show ip dhcp relay counters | Dhcp Packets | Interface | Rcvd Fwdd Drop | Last Cleared ----------|----- ---- -----|--------------------- All Req | 376 376 0 | 4 days, 19:55:12 ago All Resp | 277 277 0 | | | Vlan1001 | 207 148 0 | 4 days, 19:54:24 ago Vlan1045 | 376 277 0 | 4 days, 19:54:24 ago switch# clear ip dhcp relay counters interface vlan 1045 | Dhcp Packets | Interface | Rcvd Fwdd Drop | Last Cleared ----------|----- ---- -----|--------------------- All Req | 380 380 0 | 4 days, 21:19:17 ago All Resp | 281 281 0 | | | Vlan1000 | 207 148 0 | 4 days, 21:18:30 ago Vlan1045 | 0 0 0 | 0:00:07 ago - These commands clear all DHCP relay counters on the switch.
switch(config-if-Vl1045)# exit switch(config)# clear ip dhcp relay counters switch(config)# show ip dhcp relay counters | Dhcp Packets | Interface | Rcvd Fwdd Drop | Last Cleared ----------|----- ---- -----|------------- All Req | 0 0 0 | 0:00:03 ago All Resp | 0 0 0 | | | Vlan1000 | 0 0 0 | 0:00:03 ago Vlan1045 | 0 0 0 | 0:00:03 ago
clear ip dhcp snooping counters
The clear ip dhcp snooping counters command resets the DHCP snooping packet counters.
Command Mode
Privileged EXEC
Command Syntax
clear ip dhcp snooping counters [COUNTER_TYPE]
Parameters
- no parameterCounters for each VLAN.
- debug Aggregate counters and drop cause counters.
- This command clears the DHCP snooping counters for each VLAN.
switch# clear ip dhcp snooping counters switch# show ip dhcp snooping counters | Dhcp Request Pkts | Dhcp Reply Pkts | Vlan | Rcvd Fwdd Drop | Rcvd Fwdd Drop | Last Cleared -----|------ ----- ------|----- ---- ------|------------- 100 | 0 0 0 | 0 0 0 | 0:00:10 ago switch# - This command clears the aggregate DHCP snooping counters.
switch# clear ip dhcp snooping counters debug switch# show ip dhcp snooping counters debug Counter Snooping to Relay Relay to Snooping ----------------------------- ----------------- ----------------- Received 0 0 Forwarded 0 0 Dropped - Invalid VlanId 0 0 Dropped - Parse error 0 0 Dropped - Invalid Dhcp Optype 0 0 Dropped - Invalid Info Option 0 0 Dropped - Snooping disabled 0 0 Last Cleared: 0:00:08 ago switch#
clear ip multicast count
The clear ip multicast count command clears all counters associated with the multicast traffic.
Command Mode
Gobal Configuration
Command Syntax
clear ip multicast count [group_address [source_address]]
- no parameters Clears all counts of the multicast route traffic.
- group_address Clears the multicast traffic count of the specified group address.
- source_address Clears the multicast traffic count of the specified group and source addresses.
Guidelines
This command functions only when the ip multicast count command is enabled.
- This command clears all counters associated with the multicast traffic.
switch(config)# clear ip multicast count - This command clears the multicast traffic count of the specified group address.
switch(config)# clear ip multicast count 16.39.24.233
cli vrf
The cli vrf command specifies the context-active VRF. The context-active VRF determines the default VRF that VRF-context aware commands use when displaying routing table data.
Command Mode
Privileged EXEC
Command Syntax
cli vrf [VRF_ID]
Parameters
- vrf_name Name of user-defined VRF.
- default System-default VRF.
Guidelines
VRF-context aware commands include:
Related Commands
The show routing-context vrf command displays the context-active VRF.
These commands specify magenta as the context-active VRF, then display the context-active VRF.
switch# cli vrf magenta
switch# show routing-context vrf
Current VRF routing-context is magenta
switch#compress
The compress command increases the hardware resources available for the specified prefix lengths.
The no compress command removes the 2-to-1 compression configuraion from the running-config.
Command Mode
Global Configuration
Command Syntax
ip hardware fib optimize prefix-length prefix-lengthexpand prefix-length compress
no ip hardware fib optimize prefix-length prefix-lengthexpand prefix-length compress
Parameters
compress Allows configuring up to one compressed prefix length.
switch(config)# ip hardware fib optimize prefix-length 20 24 expand 19 23 compress 25
! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimizeddescription (VRF)
The description command adds a text string to the configuration mode VRF. The string has no functional impact on the VRF.
The no description and default description commands remove the text string from the configuration mode VRF by deleting the corresponding description command from running-config.
Command Mode
VRF Configuration
Command Syntax
description label_text
no description
default description
Parameters
label_text Character string assigned to the VRF configuration.
Related Commands
The vrf instance command places the switch in VRF configuration mode.
switch(config)# vrf instance magenta
switch(config-vrf-magenta)# description This is the first vrf
switch(config-vrf-magenta)# show active
vrf instance magenta
description This is the first vrf
switch(config-vrf-magenta)#dhcp relay
The dhcp relay command places the switch in the DHCP relay mode. This command is executed under global configuration mode.
The no dhcp relay command removes DHCP relay configuration from the running-config.
Command Mode
Global Configuration Mode
Command Syntax
dhcp relay
no dhcp relay
Example
switch(config)# dhcp relay
switch(config-dhcp-relay)#dhcp server
The dhcp server command places the switch in the DHCP relay mode. This command is executed under global configuration mode.
The no dhcp server command removes DHCP relay configuration from the running-config.
Command Mode
Global Configuration Mode
Command Syntax
dhcp server
no dhcp server
Example
switch(config)# dhcp server
switch(config-dhcp-server)#dhcp server client
The dhcp server client command configures client options for the DHCP server.Execute this command under the dhcp server configuration mode.
Command Mode
DHCP Server Configuration Mode
Command Syntax
dhcp server client class [ipv4|ipv6] definition client_class assignments [default-gateway|dns|lease|option|private-option|tftp]
Parameters
- [ipv4|ipv6] - Select the IP address family.
- definition client_class - Add a class for the client definition.
- default-gateway - Configure the client class default gateway sent to DHCP clients.
- dns - Configure the client class DNS.
- lease - Configure the client class lease.
- option - Configure the client class DHCP options.
- private-option - Configure the client class's private options.
- tftp - Configure the client class's TFTP options
Example
switch(config-dhcp-server)#client class ipv4 definition test1 default-gateway 10.0.0.1dhcp server debug
The dhcp server debug log command configures DHCP server debugging configuration. Execute this command in the dhcp server configuration mode.
Command Mode
DHCP Server Configuration Mode
Command Syntax
dhcp server debug log file
Parameters
- log file - Specify the file location to store debugging logs.
Example
switch(config-dhcp-server)#debug logdhcp server dns
The dhcp server dns command configures DHCP server DNS options. This command is executed under the dhcp server configuration mode.
Command Mode
DHCP Server Configuration Mode
Command Syntax
dhcp server dns [domain name domain_name ] [server [ipv4|ipv6] ip_address
Parameters
- domain name domain_name - Specify the domain name of the DNS server.
- server [ipv4|ipv6] ip_address - Specify the DNS server as IPv4 or IPv6 and the IP address of the server.
Example
switch(config-dhcp-server)#dns server ipv4 192.168.10.5dhcp server lease
The dhcp server lease command configures DHCP server lease options. Execute this command under the dhcp server configuration mode.
Command Mode
DHCP Server Configuration Mode
Command Syntax
dhcp server lease time [ipv4|ipv6] days days hourshours minutesminutes
Parameters
- [ipv4|ipv6] - Configure the lease for IPv4 or IPv6.
- days days - Specify the number of days for the lease to be in effect from 0 to 2000 days.
- hourshours - Specify the number of hours for the lease to be in effect from 0 to 23 hours.
- minutesminutes - Specify the number of minutes for the lease to be in effect from 0 to 59 minutes.
Example
switch(config-dhcp-server)#dns lease time ipv4 10 daysdhcp server option
The dhcp server option command configures DHCP server options. This command is executed under the dhcp server configuration mode.
Command Mode
DHCP Server Configuration Mode
Command Syntax
dhcp server option [ipv4|ipv6] code [always-send data type [hex |string] data]] >quoted_string >hex [client-id disable] hourshours minutesminutes
Parameters
- [ipv4|ipv6] - Configure the option for IPv4 or IPv6.
- code- Specify the option number from the DHCP options.
- [always-send data type [hex |string] data]] >quoted_string >hex - Specify to send the option whether or not the client requested it.
- client-id disable - Prevent the DHCPv4 server from sending back the client ID.
Example
switch(config-dhcp-server)#option ipv4 option 67dhcp server private-option
The dhcp server private-option command configures DHCP server private options. This command is executed under the dhcp server configuration mode.
Command Mode
DHCP Server Configuration Mode
Command Syntax
dhcp server private-option [ipv4|ipv6] code [always-send data type [hex |string] data]] >quoted_string >hex
Parameters
- [ipv4|ipv6] - Configure the option for IPv4 or IPv6.
- code- Specify the option number from 224 to 254.
- [always-send data type [hex |string] data]] quoted_string >hex - Specify to send the option whether or not the client requested it.
Example
switch(config-dhcp-server)#option ipv4 private-option 225 always-send private-option ipv4 225 always-send type string data "Code Sent"dhcp server subnet
The dhcp server subnet command configures DHCP server subnet options. Execute this command under the dhcp server configuration mode.
Command Mode
DHCP Server Configuration Mode
Command Syntax
dhcp server subnet ipv4_address ipv6_address
Parameters
- ipv4_address> - Configure the IPv4 subnet.
- ipv6_address - Configure the IPv6 subnet.
Example
switch(config-dhcp-server)#subnet 198.168.0.0/24dhcp server subnet client
The dhcp server subnet [ipv4 | ipv6] client command configures client options for the DHCP server. Execute this command in the dhcp server subnet configuration mode.
Command Mode
DHCP Server Subnet Configuration Mode
Command Syntax
dhcp server subnet [ipv4|ipv6] client class defintion client_class [default-gateway|dns|lease|name|range|reservations|tftp]
Parameters
- [ipv4|ipv6] - Select the IP address family.
- definition client_class - Add a class for the client definition.
- default-gateway ip_address - Configure the client class default gateway sent to DHCP clients.
- dns server - Configure the client class DNS.
- lease days hourshours minutesminutes - Configure the client class lease in days, hours, and minutes.
- name name - Configure the subnet name.
- range ip_address_start ip_address_end - Configure the range of IP addresses for the subnet.
- reservations mac-address mac_address [hostname | ipv4-address]- Configure the MAC address to use for reservations.
- tftp - Configure the client class's TFTP options
Example
switch(config-dhcp-server)#client class ipv4 definition test1 default-gateway 10.0.0.1dhcp server tftp
The dhcp server tftp command configures DHCP server TFTP options. Execute this command under the dhcp server configuration mode.
Command Mode
DHCP Server Configuration Mode
Command Syntax
dhcp server tftp server [file [ipv4|ipv6] file_name] [option [150|66]] ipv4
Parameters
- file [ipv4|ipv6] file_name> - Configure the IPv4 or IPv6 boot file name.
- option [150|66]] ipv4 ip_address - Configure the TFTP DHCP option as 150 or 66 with an IPv4 address.
Example
switch(config-dhcp-server)#tftp option 150 ipv4 198.168.0.11dhcp server vendor-option
The dhcp server vendor-option command configures the DHCP server vendor identifier options. Execute this command under the dhcp server configuration mode.
Command Mode
DHCP Server Configuration Mode
Command Syntax
dhcp server vendor-option ipv4 vendor_id default vendor_id sub-option sub-option_code
Parameters
- vendor_id - Configure the vendor identifier.
- default vendor_id - Set as the default vendor specific option.
- sub-option sub-option_code - Set the sub-option code from 1-254.
Example
switch(config-dhcp-server)#vendor-option 1:4:c0:0:2:8dhcp server vendor-option ipv4 sub-option
The dhcp server vendor-option command configures the DHCP server vendor identifier options. Execute this command under the dhcp server configuration mode.
Command Mode
DHCP Server Configuration Mode
Command Syntax
dhcp server vendor-option ipv4 vendor_id default vendor_id sub-option sub-option_code type [array | ipv4-address | string] array [ipv4-address data ip_address [string data quoted_string
Parameters
- vendor_id - Configure the vendor identifier.
- default vendor_id - Set as the default vendor specific option.
- sub-option sub-option_code - Set the sub-option code from 1-254.
Example
switch(config-dhcp-server)#vendor-option 1:4:c0:0:2:8interface tunnel
The interface tunnel command places the switch in interface-tunnel configuration mode.
Interface-tunnel configuration mode is not a group change mode; running-config is changed immediately after commands are executed.
The no interface tunnel command deletes the specified interface tunnel configuration.
The exit command returns the switch to the global configuration mode.
Command Mode
Global Configuration
Command Syntax
interface tunnel number
no interface tunnel number
Parameter
number Tunnel interface number. Values range from 0 to 255.
switch(config)# interface tunnel 10
switch(config-if-Tu10)#ip arp inspection limit
The ip arp inspection limit command err-disables the interface if the incoming ARP rate exceeds the configured value rate limit the incoming ARP packets on an interface.
Command Mode
EXEC
Command Syntax
ip arp inspection limit [ RATE pps] [BURST_INTERVAL sec | none]
no ip arp inspection limit [ RATE pps] [BURST_INTERVAL sec | none]
default ip arp inspection limit [ RATE pps] [BURST_INTERVAL sec | none]
- RATE Specifies the ARP inspection limit rate in packets per second.
- pps ARP inspection limit rate packets per second.
- BURST_INTERVAL Specifies the ARP inspection limit burst interval.
- sec Burst interval second.
- This command configures the rate limit of incoming ARP packets to errdisable the interface when the incoming ARP rate exceeds the configured value, sets the rate to 512 (which is the upper limit for the number of invalid ARP packets allowed per second), and sets the burst consecutive interval over which the interface is monitored for a high ARP rate to 11 seconds.
switch(config)# ip arp inspection limit rate 512 burst interval 11 switch(config)# - This command displays verification of the interface specific configuration.
switch(config)# interface ethernet 3/1 switch(config)# ip arp inspection limit rate 20 burst interval 5 switch(config)# interface Ethernet 3/3 switch(config)# ip arp inspection trust switch(config)# show ip arp inspection interfaces Interface Trust State Rate (pps) Burst Interval ------------- ----------- ---------- -------------- Et3/1 Untrusted 20 5 Et3/3 Trusted None N/A switch(config)#
ip arp inspection logging
The ip arp inspection logging command enables logging of incoming ARP packets on the interface if the rate exceeds the configured value.
Command Mode
EXEC
Command Syntax
ip arp inspection logging [RATE pps ][BURST_INTERVAL sec | none]
no ip arp inspection logging [RATE pps ][BURST_INTERVAL sec | none]
default ip arp inspection logging [RATE pps ][BURST_INTERVAL sec | none]
- RATE Specifies the ARP inspection limit rate in packets per second.
- <pps> ARP inspection limit rate packets per second.
- BURST_INTERVAL Specifies the ARP inspection limit burst interval.
-
sec Burst interval second.
-
switch(config)# ip arp inspection logging rate 2048 burst interval 15
switch(config)#ip arp inspection trust
The ip arp inspection trust command configures the trust state of an interface. By default, all interfaces are untrusted.
Command Mode
EXEC
Command Syntax
ip arp inspection trust
no ip arp inspection trust
default ip arp inspection trust
- This command configures the trust state of an interface.
switch(config)# ip arp inspection trust switch(config)# - This command configures the trust state of an interface to untrusted.
switch(config)# no ip arp inspection trust switch(config)# - This command configures the trust state of an interface to its default (untrusted).
switch(config)# default ip arp inspection trust switch(config)#
ip arp inspection vlan
The ip arp inspection vlan command enables ARP inspection. ARP requests and responses on untrusted interfaces are intercepted on specified VLANs, and intercepted packets are verified to have valid IP-MAC address bindings. All invalid ARP packets are dropped. On trusted interfaces, all incoming ARP packets are processed and forwarded without verification. By default, ARP inspection is disabled on all VLANs.
Command Mode
EXEC
Command Syntax
ip arp inspection vlan [LIST]
Parameters
LIST Specifies the VLAN interface number.
- This command enables ARP inspection on VLANs 1 through 150.
switch(config)# ip arp inspection vlan 1 - 150 switch(config)# - This command disables ARP inspection on VLANs 1 through 150.
switch(config)# no ip arp inspection vlan 1 - 150 switch(config)# - This command sets the ARP inspection default to VLANs 1 through 150.
switch(config)# default ip arp inspection vlan 1 - 150 switch(config)# - These commands enable ARP inspection on multiple VLANs 1 through 150 and 200 through 250.
switch(config)# ip arp inspection vlan 1-150,200-250 switch(config)#
ip dhcp relay all-subnets
The ip dhcp relay all-subnets command configures the DHCP smart relay status on the configuration mode interface. DHCP smart relay supports forwarding DHCP requests with a client’s secondary IP addresses in the gateway address field. Enabling DHCP smart relay on an interface requires that DHCP relay is also enabled on that interface.
By default, an interface assumes the global DHCP smart relay setting as configured by the ip dhcp relay all-subnets default command. The ip dhcp relay all-subnets command, when configured, takes precedence over the global smart relay setting.
The no ip dhcp relay all-subnets command disables DHCP smart relay on the configuration mode interface. The default ip dhcp relay all-subnets command restores the interface’s to the default DHCP smart relay setting, as configured by the ip dhcp relay all-subnets default command, by removing the corresponding ip dhcp relay all-subnets or no ip dhcp relay all-subnets statement from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Port-channel Configuration
Interface-VLAN Configuration
Command Syntax
ip dhcp relay all-subnets
no ip dhcp relay all-subnets
default ip dhcp relay all-subnets
- This command enables DHCP smart relay on VLAN interface 100.
switch(config)# interface vlan 100 switch(config-if-Vl100)# ip helper-address 10.4.4.4 switch(config-if-Vl100)# ip dhcp relay all-subnets switch(config-if-Vl100)# show ip dhcp relay DHCP Relay is active DHCP Relay Option 82 is disabled DHCP Smart Relay is enabled Interface: Vlan100 DHCP Smart Relay is enabled DHCP servers: 10.4.4.4 switch(config-if-Vl100)# - This command disables DHCP smart relay on VLAN interface 100.
switch(config-if-Vl100)# no ip dhcp relay all-subnets switch(config-if-Vl100)# show active interface Vlan100 no ip dhcp relay all-subnets ip helper-address 10.4.4.4 switch(config-if-Vl100)# show ip dhcp relay DHCP Relay is active DHCP Relay Option 82 is disabled DHCP Smart Relay is enabled Interface: Vlan100 DHCP Smart Relay is disabled DHCP servers: 10.4.4.4 switch(config-if-Vl100)# - This command enables DHCP smart relay globally, configures VLAN interface 100 to use the global setting, then displays the DHCP relay status.
switch(config)# ip dhcp relay all-subnets default switch(config)# interface vlan 100 switch(config-if-Vl100)# ip helper-address 10.4.4.4 switch(config-if-Vl100)# default ip dhcp relay switch(config-if-Vl100)# show ip dhcp relay DHCP Relay is active DHCP Relay Option 82 is disabled DHCP Smart Relay is enabled Interface: Vlan100 Option 82 Circuit ID: 333 DHCP Smart Relay is enabled DHCP servers: 10.4.4.4 switch(config-if-Vl100)#
ip dhcp relay all-subnets default
The ip dhcp relay all-subnets default command configures the global DHCP smart relay setting. DHCP smart relay supports forwarding DHCP requests with a client’s secondary IP addresses in the gateway address field. The default global DHCP smart relay setting is disabled.
The global DHCP smart relay setting is applied to all interfaces for which an ip dhcp relay all-subnets statement is not configured. Enabling DHCP smart relay on an interface requires that DHCP relay is also enabled on that interface.
The no ip dhcp relay all-subnets default and default ip dhcp relay all-subnets default commands restore the global DHCP smart relay default setting of disabled by removing the ip dhcp relay all-subnets default command from running-config.
Command Mode
Global Configuration
Command Syntax
ip dhcp relay all-subnets default
no ip dhcp relay all-subnets default
default ip dhcp relay all-subnets default
- ip helper-address Enables the DHCP relay agent on a configuration mode interface.
- ip dhcp relay all-subnets Enables the DHCP smart relay agent on a configuration mode interface.
switch(config)# ip dhcp relay all-subnets default
switch(config)#ip dhcp relay always-on
The ip dhcp relay always-on command enables the switch DHCP relay agent on the switch regardless of the DHCP relay agent status on any interface. By default, the DHCP relay agent is enabled only if at least one routable interface is configured with an ip helper-address statement.
The no ip dhcp relay always-on and default ip dhcp relay always-on commands remove the ip dhcp relay always-on command from running-config.
Command Mode
Global Configuration
Command Syntax
ip dhcp relay always-on
no ip dhcp relay always-on
default ip dhcp relay always-on
Related Commands
switch(config)# ip dhcp relay always-on
switch(config)#ip dhcp relay information option (Global)
The ip dhcp relay information option command configures the switch to attach tags to DHCP requests before forwarding them to the DHCP servers designated by the ip helper-address commands. The command specifies the tag contents for packets forwarded by the configured interface. The default value for each interface configured with an ip helper-address is the name and number of the interface.
The no ip dhcp relay information option and default ip dhcp relay information option commands restore the switch default setting of not attaching tags to DHCP requests by removing the ip dhcp relay information option command from running-config.
Command Mode
Global Configuration
Command Syntax
ip dhcp relay information option
no ip dhcp relay information option
default ip dhcp relay information option
Related Commands
This command enables the attachment of tags to DHCP requests forwarded to DHCP server addresses.
switch(config)# ip dhcp relay information option
switch(config)#ip dhcp relay information option circuit-id
The ip dhcp relay information option circuit-id command specifies the content of tags that the switch attaches to DHCP requests before they are forwarded from the configuration mode interface to DHCP server addresses specified by ip helper-address commands. Tags are attached to outbound DHCP requests only if the information option is enabled on the switch (ip dhcp relay information option circuit-id).
The no ip dhcp relay information option circuit-id and default ip dhcp relay information option circuit-id commands restore the default content setting for the configuration mode interface by removing the corresponding command from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Loopback Configuration
Interface-Management Configuration
Interface-Port-channel Configuration
Interface-VLAN Configuration
Command Syntax
ip dhcp relay information option circuit-id id_label
no ip dhcp relay information option circuit-id
default ip dhcp relay information option circuit-id
Parameters
id_label Tag content. Format is alphanumeric characters (maximum 15 characters).
This command configures x-1234 as the tag content for packets send from VLAN 200.
switch(config)# interface vlan 200
switch(config-if-Vl200)# ip dhcp relay information option circuit-id x-1234
switch(config-if-Vl200)#ip dhcp snooping
The ip dhcp snooping command enables DHCP snooping globally on the switch. DHCP snooping is a set of Layer 2 processes that can be configured on LAN switches and used with DHCP servers to control network access to clients with specific IP/MAC addresses. The switch supports Option-82 insertion, which is a DHCP snooping process that allows relay agents to provide remote-ID and circuit-ID information to DHCP reply and request packets. DHCP servers use this information to determine the originating port of DHCP requests and associate a corresponding IP address to that port. DHCP servers use port information to track host location and IP address usage by authorized physical ports.
DHCP snooping uses the information option (Option-82) to include the switch MAC address (router-ID) along with the physical interface name and VLAN number (circuit-ID) in DHCP packets. After adding the information to the packet, the DHCP relay agent forwards the packet to the DHCP server as specified by the DHCP protocol.
- DHCP snooping is globally enabled.
- Insertion of option-82 information in DHCP packets is enabled.
- DHCP snooping is enabled on the specified VLAN.
- DHCP relay is enabled on the corresponding VLAN interface.
The no ip dhcp snooping and default ip dhcp snooping commands disables global DHCP snooping by removing the ip dhcp snooping command from running-config.
Command Mode
Global Configuration
Command Syntax
ip dhcp snooping
no ip dhcp snooping
default ip dhcp snooping
- ip dhcp snooping information option enables insertion of option-82 snooping data.
- ip helper-address enables the DHCP relay agent on a configuration mode interface.
switch(config)# show ip dhcp snooping
DHCP Snooping is disabled
switch(config)# ip dhcp snooping
switch(config)# show ip dhcp snooping
DHCP Snooping is enabled
DHCP Snooping is not operational
DHCP Snooping is configured on following VLANs:
None
DHCP Snooping is operational on following VLANs:
None
Insertion of Option-82 is disabled
switch(config)#ip dhcp snooping bridging
The ip dhcp snooping bridging command enables the DHCP snooping bridging configuration.
The no ip dhcp snooping bridging command removes the DHCP snooping bridging configuration from the running-config.
Command Mode
Global Configuration Mode
Command Syntax
ip dhcp snooping bridging
no ip dhcp snooping bridging
Example
switch# configure
switch(config)# ip dhcp snooping bridgingip dhcp snooping information option
The ip dhcp snooping information option command enables the insertion of option-82 DHCP snooping information in DHCP packets on VLANs where DHCP snooping is enabled. DHCP snooping is a layer 2 switch process that allows relay agents to provide remote-ID and circuit-ID information to DHCP reply and request packets. DHCP servers use this information to determine the originating port of DHCP requests and associate a corresponding IP address to that port.
DHCP snooping uses information option (Option-82) to include the switch MAC address (router-ID) along with the physical interface name and VLAN number (circuit-ID) in DHCP packets. After adding the information to the packet, the DHCP relay agent forwards the packet to the DHCP server through DHCP protocol processes.
- DHCP snooping is globally enabled.
- Insertion of option-82 information in DHCP packets is enabled.
- DHCP snooping is enabled on the specified VLAN.
- DHCP relay is enabled on the corresponding VLAN interface.
When global DHCP snooping is not enabled, the ip dhcp snooping information option command persists in running-config without any operational effect.
The no ip dhcp snooping information option and default ip dhcp snooping information option commands disable the insertion of option-82 DHCP snooping information in DHCP packets by removing the ip dhcp snooping information option statement from running-config.
Command Mode
Global Configuration
Command Syntax
ip dhcp snooping information option
no ip dhcp snooping information option
default ip dhcp snooping information option
- ip dhcp snooping globally enables DHCP snooping.
- ip helper-address enables the DHCP relay agent on a configuration mode interface.
switch(config)# ip dhcp snooping information option
switch(config)# show ip dhcp snooping
DHCP Snooping is enabled
DHCP Snooping is operational
DHCP Snooping is configured on following VLANs:
100
DHCP Snooping is operational on following VLANs:
100
Insertion of Option-82 is enabled
Circuit-id format: Interface name:Vlan ID
Remote-id: 00:1c:73:1f:b4:38 (Switch MAC)
switch(config)#ip dhcp snooping vlan
The ip dhcp snooping vlan command enables DHCP snooping on specified VLANs. DHCP snooping is a Layer 2 process that allows relay agents to provide remote-ID and circuit-ID information in DHCP packets. DHCP servers use this data to determine the originating port of DHCP requests and associate a corresponding IP address to that port. DHCP snooping is configured on a global and VLAN basis.
- DHCP snooping is globally enabled.
- Insertion of option-82 information in DHCP packets is enabled.
- DHCP snooping is enabled on the specified VLAN.
- DHCP relay is enabled on the corresponding VLAN interface.
When global DHCP snooping is not enabled, the ip dhcp snooping vlan command persists in running-config without any operational affect.
The no ip dhcp snooping information option and default ip dhcp snooping information option commands disable DHCP snooping operability by removing the ip dhcp snooping information option statement from running-config.
Command Mode
Global Configuration
Command Syntax
ip dhcp snooping vlan v_range
no ip dhcp snooping vlan v_range
default ip dhcp snooping vlan v_range
- v_range VLANs upon which snooping is enabled. Formats include a number, a number range, or a comma-delimited list of numbers and ranges. Numbers range from 1 to 4094.
- The ip dhcp snooping command globally enables DHCP snooping.
- The ip dhcp snooping vlan command enables insertion of option-82 snooping data.
- The ip helper-address command enables the DHCP relay agent on a configuration mode interface.
switch(config)# ip dhcp snooping
switch(config)# ip dhcp snooping information option
switch(config)# ip dhcp snooping vlan 100
switch(config)# interface vlan 100
switch(config-if-Vl100)# ip helper-address 10.4.4.4
switch(config-if-Vl100)# show ip dhcp snooping
DHCP Snooping is enabled
DHCP Snooping is operational
DHCP Snooping is configured on following VLANs:
100
DHCP Snooping is operational on following VLANs:
100
Insertion of Option-82 is enabled
Circuit-id format: Interface name:Vlan ID
Remote-id: 00:1c:73:1f:b4:38 (Switch MAC)
switch(config)#ip hardware fib ecmp resilience
The ip hardware fib ecmp resilience command enables resilient ECMP for the specified IP address prefix and configures a fixed number of next hop entries in the hardware ECMP table for that prefix. In addition to specifying the maximum number of next hop addresses that the table can contain for the prefix, the command includes a redundancy factor that allows duplication of each next hop address. The fixed table space for the address is the maximum number of next hops multiplied by the redundancy factor.
Resilient ECMP is useful when it is not desirable for routes to be rehashed due to link flap, as when ECMP is being used for load balancing.
The no ip hardware fib ecmp resilience and default ip hardware fib ecmp resilience commands restore the default hardware ECMP table management by removing the ip hardware fib ecmp resilience command from running-config .
Command Mode
Global Configuration
Command Syntax
ip hardware fib ecmp resilience net_addr capacity nhop_max redundancy duplicates
no ip hardware fib ecmp resilience net_addr
default ip hardware fib ecmp resilience net_addr
- net_addr IP address prefix managed by command. (CIDR or address-mask).
- nhop_max Maximum number of nexthop addresses for specified IP address prefix. Value range varies by platform:
- Helix: <2 to 64>
- Trident: <2 to 32>
- Trident II: <2 to 64>
- duplicates Specifies the redundancy factor. Value ranges from 1 to 128.
switch(config)# ip hardware fib ecmp resilience 10.14.2.2/24 capacity 6 redundancy 4
switch(config)#ip hardware fib next-hop resource optimization
The ip hardware fib next-hop resource optimization command is used to enable or disable the resource optimization features on the switch. By default, RECMP is enabled on the switch.
The no hardware fib next-hop resource optimization command removes all the resource optimization features running on the switch.
Command Mode
Global Configuration Mode
Command Syntax
ip hardware fib next-hop resource optimization OPTIONS
no ip hardware fib next-hop resource optimization OPTIONS
- The following two options are allowed to configure with this command:
- disabled Disable hardware resource optimization for adjacency programming.
- thresholds Utilization percentage for starting or stopping optimization. The resource utilization percentage value ranges from 0 to 100. It can be set to low and high.
- The following command is used to disable all hardware resource optimization features on the switch:
switch# configure terminal switch(config)# ip hardware fib next-hop resource optimization disabled - The following command is used to configure the thresholds for starting and stopping the optimization:
switch(config)# ip hardware fib next-hop resource optimization thresholds low 20 high 80
ip hardware fib optimize
The ip hardware fib optimize command enables IPv4 route scale. Restart the platform Layer 3 agent to ensure optimization of IPv4 routes with the agent SandL3Unicast terminate command for the configuration mode interface.
Command Mode
Global Configuration
Command Syntax
ip hardware fib optimize exact-match prefix-length prefix-length prefix-length
Parameters
prefix-length The length of the prefix equal to 12, 16, 20, 24, 28, or 32. Optionally, add one additional prefix-length limited to the prefix-length of 32.
- The agent SandL3Unicast terminate command restarts the Layer 3 agent to ensure optimization of IPv4 routes.
- The show platform arad ip route command shows resources for all IPv4 routes in hardware. Routes with additional hardware resources appear with an asterisk (*).
-
The show platform arad ip route summary command displays hardware resource usage of IPv4 routes.
Examples
switch(config)# ip hardware fib optimize exact-match prefix-length 12 32
! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimizedOne of the two prefixes in this command has a prefix-length of 32, required in the instance when adding two prefixes. For this command to take effect, restart the platform Layer 3 agent.
switch(config)# agent SandL3Unicast terminate
SandL3Unicast was terminatedRestarting the platform Layer 3 agent results in deletion of all IPv4 routes, and then re-added to the hardware.
switch(config)# ip hardware fib optimize exact-match prefix-length 32 16
! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimizedOne of the two prefixes in this command is a prefix-length of 32, required when adding two prefixes. For this command to take effect, restart the platform Layer 3 agent.
switch(config)# agent SandL3Unicast terminate
SandL3Unicast was terminatedRestarting the platform Layer 3 agent results in deletion of all IPv4 routes, and then re-added to the hardware.
switch(config)# ip hardware fib optimize exact-match prefix-length 24
! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimizedIn this instance, add one prefix-length, and does not requirea prefix-length of 32.For this command to take effect, restart the platform Layer 3 agent.
switch(config)# agent SandL3Unicast terminate
SandL3Unicast was terminatedRestarting the platform Layer 3 agent results in deletion of all IPv4 routes, and then re-added to the hardware.
switch(config)# ip hardware fib optimize exact-match prefix-length 32
! Please restart layer 3 forwarding agent to ensure IPv4 routes are optimizedFor this command to take effect, restart the platform Layer 3 agent.
switch(config)# agent SandL3Unicast terminate
SandL3Unicast was terminatedRestarting the platform Layer 3 agent results in deletion of all IPv4 routes, and then re-added to the hardware.
switch(config)# no ip hardware fib optimize exact-match prefix-length 12 32
! Please restart layer 3 forwarding agent to ensure IPv4 routes are not optimizedOne of the two prefixes in this command has a prefix-length of 32,required when configuring two prefixes. For this command to take effect, restart the platform Layer 3 agent.
ip helper-address
The ip helper-address command enables the DHCP relay agent on the configuration mode interface and specifies a forwarding address for DHCP requests. An interface that is configured with multiple helper-addresses forwards DHCP requests to all specified addresses.
The no ip helper-address and default ip helper-address commands remove the corresponding ip helper-address command from running-config. Commands that do not specify an IP helper-address remove all helper-addresses from the interface.
Command Mode
Interface-Ethernet Configuration
Interface-Port-channel Configuration
Interface-VLAN Configuration
Command Syntax
ip helper-address ipv4_addr [vrf vrf_name][source-address ipv4_addr | source-interface INTERFACES]
no ip helper-address [ipv4_addr]
default ip helper-address [ipv4_addr]
- vrf vrf_name Specifies the user-defined VRF for DHCP server.
- ipv4_addr Specifies the DHCP server address accessed by interface.
- source-address ipv4_addr Specifies the source IPv4 address to communicate with DHCP server.
- source-interface INTERFACES Specifies the source interface to communicate with DHCP server. Options include:
- Ethernet eth_num Specifies the Ethernet interface number.
- Loopback lpbck_num Specifies the loopback interface number. Value ranges from 0 to 1000.
- Management mgmt_num Specifies the management interface number. Accepted values are 1 and 2.
- Port-Channel {int_num | sub_int_num} Specifies the port-channel interface or subinterface number. Value of interface ranges from 1 to 2000. Value of sub-interface ranges from 1 to 4094.
- Tunnel tnl_num Specifies the tunnel interface number. Value ranges from 0 to 255.
- VLAN vlan_num Specifies the Ethernet interface number. Value ranges from 1 to 4094.
Guidelines
If the source-address parameter is specified, then the DHCP client receives an IPv4 address from the subnet of source IP address. The source-address must be one of the configured addresses on the interface.
- This command enables DHCP relay on the VLAN interface 200; and configure the switch to forward DHCP requests received on this interface to the server at 10.10.41.15.
switch(config)# interface vlan 200 switch(config-if-Vl200)# ip helper-address 10.10.41.15 switch(config-if-Vl200)# show active interface Vlan200 ip helper-address 10.10.41.15 switch(config-if-Vl200)# - This command enables DHCP relay on the interface ewthernet 1/2; and configures the switch to use 2.2.2.2 as the source IP address when relaying IPv4 DHCP messages to the server at 1.1.1.1.
switch(config)# interface ethernet 1/2 switch(config-if-Et1/2)# ip helper-address 1.1.1.1 source-address 2.2.2.2 switch(config-if-Et1/2)#
ip icmp redirect
The ip icmp redirect command enables the transmission of ICMP redirect messages. Routers send ICMP redirect messages to notify data link hosts of the availability of a better route for a specific destination.
The no ip icmp redirect disables the switch from sending ICMP redirect messages.
Command Mode
Global Configuration
Command Syntax
ip icmp redirect
no ip icmp redirect
default ip icmp redirect
This command disables the redirect messages.
switch(config)# no ip icmp redirect
switch(config)# show running-config
<-------OUTPUT OMITTED FROM EXAMPLE-------->
!
no ip icmp redirect
ip routing
!
<-------OUTPUT OMITTED FROM EXAMPLE-------->
switch(config)#ip load-sharing
The ip load-sharing command provides the hash seed to an algorithm that the switch uses to distribute data streams among multiple equal-cost routes to an individual IPv4 subnet.
In a network topology using Equal-Cost Multipath routing, all switches performing identical hash calculations may result in hash polarization, leading to uneven load distribution among the data paths. Hash polarization is avoided when switches use different hash seeds to perform different hash calculations.
The no ip load-sharing and default ip load-sharing commands return the hash seed to the default value of zero by removing the ip load-sharing command from running-config.
Command Mode
Global Configuration
Command Syntax
ip load-sharing HARDWARE seed
no ip load-sharing HARDWARE
default ip load-sharing HARDWARE
- HARDWARE The ASIC switching device. The available option depend on the switch platform. Verify available options with the CLI ? command.
- arad
- fm6000
- petraA
- trident
- seed The hash seed. Value range varies by switch platform. The default value on all platforms is 0.
- when HARDWARE=arad seed ranges from 0 to 2.
- when HARDWARE=fm6000 seed ranges from 0 to 39.
- when HARDWARE=petraA seed ranges from 0 to 2.
- when HARDWARE=trident seed ranges from 0 to 5.
switch(config)# ip load-sharing fm6000 1
switch(config)# ip local-proxy-arp
The ip local-proxy-arp command enables local proxy ARP (Address Resolution Protocol) on the configuration mode interface. When local proxy ARP is enabled, ARP requests received on the configuration mode interface will return an IP address even when the request comes from within the same subnet.
The no ip local-proxy-arp and default ip local-proxy-arp commands disable local proxy ARP on the configuration mode interface by removing the corresponding ip local-proxy-arp command from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Loopback Configuration
Interface-Management Configuration
Interface-Port-channel Configuration
Interface-VLAN Configuration
Command Syntax
ip local-proxy-arp
no ip local-proxy-arp
default ip local-proxy-arp
switch(config)# interface vlan 140
switch(config-if-Vl140)# ip local-proxy-arp
switch(config-if-Vl140)# show active
interface Vlan140
ip local-proxy-arp
switch(config-if-Vl140)#ip multicast count
The ip multicast count command enables the IPv4 multicast route traffic counter of group and source addresses in either bytes or packets.
The no ip multicast count command deletes all multicast counters including the routes of group and source addresses.
The no ip multicast count group_address source_addresscommand removes the current configuration of the specified group and source addresses. It does not delete the counter because the wildcard is still active.
The default ip multicast count command reverts the current counter configuration of multicast route to the default state.
Command Mode
Global Configuration
Command Syntax
ip multicast count [group_address [source_address] | bytes | packets]
no ip multicast count [group_address [source_address] | bytes | packets]
default ip multicast count [group_address [source_address] | bytes | packets]
- group_address Configures the multicast route traffic count of the specified group address.
- source_address Configures the multicast route traffic count of the specified group and source addresses.
- bytes Configures the multicast route traffic count to bytes.
- packets Configures the multicast route traffic count to packets.
Guidelines
This command is supported on the FM6000 platform only.
- This command configures the multicast route traffic count to bytes.
switch(config)# ip multicast count bytes - This command configures the multicast route traffic count of the specified group and source addresses.
switch(config)# ip multicast count 10.50.30.23 45.67.89.100 - This command deletes all multicast counters including the routes of group and source addresses.
switch(config)# no ip multicast count - This command reverts the current multicast route configuration to the default state.
switch(config)# default ip multicast count
ip proxy-arp
The ip proxy-arp command enables proxy ARP on the configuration mode interface. Proxy ARP is disabled by default. When proxy ARP is enabled, the switch responds to all ARP requests, including gratuitous ARP requests, with target IP addresses that match a route in the routing table.
The no ip proxy-arp and default ip proxy-arp commands disable proxy ARP on the configuration mode interface by removing the corresponding ip proxy-arp command from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Loopback Configuration
Interface-Management Configuration
Interface-Port-channel Configuration
Interface-VLAN Configuration
Command Syntax
ip proxy-arp
no ip proxy-arp
default ip proxy-arp
switch(config)#interface ethernet 4
switch(config-if-Et4)#ip proxy-arp
switch(config-if-Et4)#ip route
The ip route command creates a static route. The destination is a network segment; the nexthop address is either an IPv4 address or a routable port. When multiple routes exist to a destination prefix, the route with the lowest administrative distance takes precedence.
By default, the administrative distance assigned to static routes is 1. Assigning a higher administrative distance to a static route configures it to be overridden by dynamic routing data. For example, a static route with an administrative distance value of 200 is overridden by OSPF intra-area routes, which have a default administrative distance of 110.
Tags are used by route maps to filter routes. The default tag value on static routes is 0.
Multiple routes with the same destination and the same administrative distance comprise an Equal Cost Multi-Path (ECMP) route. The switch attempts to spread outbound traffic equally through all ECMP route paths. All paths comprising an ECMP are assigned identical tag values; commands that change the tag value of a path change the tag value of all paths in the ECMP.
The no ip route and default ip route commands delete the specified static route by removing the corresponding ip route command from running-config. Commands that do not list a nexthop address remove all ip route statements with the specified destination from running-config. If an ip route statement exists for the same IP address in multiple VRFs, each must be removed separately. All static routes in a user-defined VRF are deleted when the VRF is deleted.
Command Mode
Global Configuration
Command Syntax
ip route [VRF_INSTANCE] dest_net NEXTHOP [DISTANCE][TAG_OPTION][RT_NAME]
no ip route [VRF_INSTANCE] dest_net [NEXTHOP][DISTANCE]
default ip route [VRF_INSTANCE] dest_net [NEXTHOP][DISTANCE]
- VRF_INSTANCE Specifies the VRF instance being modified.
- no parameter Changes are made to the default VRF.
- vrf vrf_name Changes are made to the specified VRF.
- dest_net Destination IPv4 subnet (CIDR or address-mask notation).
- NEXTHOP Location or access method of next hop device. Options include:
- ipv4_addr An IPv4 address.
- null0 Null0 interface.
- ethernet e_num Ethernet interface specified by e_num.
- loopback l_num Loopback interface specified by l_num.
- management m_num Management interface specified by m_num.
- port-channel p_num Port-channel interface specified by p_num.
- vlan v_num VLAN interface specified by v_num.
- VXLAN vx_num VXLAN interface specified by vx_num.
- DISTANCE Administrative distance assigned to route. Options include:
- no parameter Route assigned default administrative distance of one.
- 1-255 The administrative distance assigned to route.
- TAG_OPTION Static route tag. Options include:
- no parameter Assigns default static route tag of 0.
- tag t_value Static route tag value. t_value ranges from 0 to 4294967295.
- RT_NAME Associates descriptive text to the route. Options include:
- no parameter No text is associated with the route.
- name descriptive_text The specified text is assigned to the route.
Related Command
The ip route nexthop-group command creates a static route that specifies a Nexthop Group to determine the Nexthop address.
Example
switch(config)# ip route 172.17.252.0/24 vlan 2000
switch(config)#ip routing
The ip routing command enables IPv4 routing. When IPv4 routing is enabled, the switch attempts to deliver inbound packets to destination IPv4 addresses by forwarding them to interfaces or next hop addresses specified by the forwarding table.
The no ip routing and default ip routing commands disable IPv4 routing by removing the ip routing command from running-config. When IPv4 routing is disabled, the switch attempts to deliver inbound packets to their destination MAC addresses. When this address matches the switch’s MAC address, the packet is delivered to the CPU. IP packets with IPv4 destinations that differ from the switch’s address are typically discarded. The delete-static-routes option removes static entries from the routing table.
IPv4 routing is disabled by default.
Command Mode
Global Configuration
Command Syntax
ip routing [VRF_INSTANCE]
no ip routing [DELETE_ROUTES][VRF_INSTANCE
default ip routing [DELETE_ROUTES][VRF_INSTANCE]
- DELETE_ROUTES Resolves routing table static entries when routing is disabled.
- no parameter Routing table retains static entries.
- delete-static-routes Static entries are removed from the routing table.
- VRF_INSTANCE Specifies the VRF instance being modified.
- no parameter Changes are made to the default VRF.
- vrf vrf_name Changes are made to the specified user-defined VRF.
switch(config)# ip routing
switch(config)#ip source binding
IP source guard (IPSG) is supported on Layer 2 Port-Channels, not member ports. The IPSG configuration on port channels supersedes the configuration on the physical member ports. Hence, source IP MAC binding entries should be configured on port channels. When configured on a port channel member port, IPSG does not take effect until this port is deleted from the port channel configuration.
The no ip source binding and default ip source binding commands exclude parameters from IPSG filtering, and set the default for ip source binding.
Command Mode
Interface-Ethernet Configuration
Command Syntax
ip source binding [IP_ADDRESS][MAC_ADDRESS] vlan [VLAN_RANGE] interface [INTERFACE]
no ip source binding [IP_ADDRESS][MAC_ADDRESS] vlan [VLAN_RANGE] interface [INTERFACE]
default ip source binding [IP_ADDRESS][MAC_ADDRESS] vlan [VLAN_RANGE] interface [INTERFACE]
- IP_ADDRESS Specifies the IP ADDRESS.
- MAC_ADDRESS Specifies the MAC ADDRESS.
- VLAN_RANGE Specifies the VLAN ID range.
-
INTERFACE Specifies the Ethernet interface.
switch(config)# ip source binding 10.1.1.1 0000.aaaa.1111 vlan 4094 interface
ethernet 36
switch(config)#ip verify source
The ip verify source command configures IP source guard (IPSG) applicable only to Layer 2 ports. When configured on Layer 3 ports, IPSG does not take effect until this interface is converted to Layer 2.
IPSG is supported on Layer 2 Port-Channels, not member ports. The IPSG configuration on port channels supersedes the configuration on the physical member ports. Therefore, source IP MAC binding entries should be configured on port channels. When configured on a port channel member port, IPSG does not take effect until this port is deleted from the port channel configuration.
The no ip verify source and default ip verify source commands exclude VLAN IDs from IPSG filtering, and set the default for ip verify source.
Command Mode
Interface-Ethernet Configuration
Command Syntax
ip verify source vlan [VLAN_RANGE]
no ip verify source [VLAN_RANGE]
default ip verify source
Parameters
VLAN_RANGE Specifies the VLAN ID range.
Related Commandsswitch(config)#no ip verify source vlan 1-3
switch(config)#interface ethernet 36
switch(config-if-Et36)#switchport mode trunk
switch(config-if-Et36)#switchport trunk allowed vlan 1-10
switch(config-if-Et36)#ip verify source
switch(config-if-Et36)#ip verify
The ip verify command configures Unicast Reverse Path Forwarding (uRPF) for inbound IPv4 packets on the configuration mode interface. uRPF verifies the accessibility of source IP addresses in packets that the switch forwards.
- Strict mode: uRPF verifies that a packet is received on the interface that its routing table entry specifies for its return packet.
- Loose mode: uRPF validation does not consider the inbound packet’s ingress interface only that there is a valid return path.
The no ip verify and default ip verify commands disable uRPF on the configuration mode interface by deleting the corresponding ip verify command from running-config.
Command Mode
Interface-Ethernet Configuration
Interface-Loopback Configuration
Interface-Management Configuration
Interface-Port-Channel Configuration
Interface-VLAN Configuration
Command Syntax
ip verify unicast source reachable-via RPF_MODE
no ip verify unicast
default ip verify unicast
Parameters
- any Loose mode.
- rx Strict mode.
- rx allow-default Strict mode. All inbound packets are forwarded if a default route is defined.
Guidelines
The first IPv4 uRPF implementation briefly disrupts IPv4 unicast routing. Subsequent ip verify commands on any interface do not disrupt IPv4 routing.
- This command enables uRPF loose mode on VLAN interface 17.
switch(config)#interface vlan 17 switch(config-if-Vl17)#ip verify unicast source reachable-via any switch(config-if-Vl17)#show active interface Vlan17 ip verify unicast source reachable-via any switch(config-if-Vl17)# - This command enables uRPF strict mode on VLAN interface 18.
switch(config)#interface vlan 18 switch(config-if-Vl18)#ip verify unicast source reachable-via rx switch(config-if-Vl18)#show active interface Vlan18 ip verify unicast source reachable-via rx switch(config-if-Vl18)#
ipv4 routable 240.0.0.0/4
The ipv4 routable 240.0.0.0/4 command assignes an class E addresses to an interface. When configured, the class E address traffic are routed through BGP, OSPF, ISIS, RIP, static routes and programmed to the FIB and kernel. By default, this command is disabled.
The no ipv4 routable 240.0.0.0/4 and default ipv4 routable 240.0.0.0/4 commands disable IPv4 Class E routing by removing the ipv4 routable 240.0.0.0/4 command from running-config.
IPv4 routable 240.0.0.0/4 routing is disabled by default.
Command Mode
Router General Configuration
Command Syntax
ipv4 routable 240.0.0.0/4
no ipv4 routable 240.0.0.0/4
default ipv4 routable 240.0.0.0/4
Example
switch(config)#router general
switch(config-router-general)#ipv4 routable 240.0.0.0/4platform barefoot bfrt vrf
The platform barefoot bfrt vrf command configures the forwarding plane agent on supported platforms to restart and listen on the configured VRF for connections. If left unconfigured, the default VRF is used for the IP and port for the the BfRuntime server.
Command Mode
Global Configuration
Command Syntax
platform barefoot bfrt vrf VRF name
Parameters
VRF name configured VRF for connections.
switch(config)#vrf instance management
switch(config-vrf-management)#exit
switch(config)#platform barefoot bfrt 0.0.0.0 50052
switch(config)#platform barefoot bfrt vrf <VRF name>
switch(config)#int management1
switch(config-if-Ma1)#vrf managementplatform trident forwarding-table partition
The platform trident forwarding-table partition command provides a shared table memory for L2, L3 and algorithmic LPM entries that can be partitioned in different ways.
Instead of having fixed-size tables for L2 MAC entry tables, L3 IP forwarding tables, and Longest Prefix Match (LPM) routes, the tables can be unified into a single shareable forwarding table.
The no platform trident forwarding-table partition and default platform trident forwarding-table partition commands remove the platform trident forwarding-table partition command from running-config.
Command Mode
Global Configuration
Command Syntax
platform trident forwarding-table partition SIZE
no platform trident forwarding-table partition
default platform trident forwarding-table partition
Parameters
- 0 288k l2 entries, 16k host entries, 16k lpm entries.
- 1 224k l2 entries, 80k host entries, 16k lpm entries.
- 2 160k l2 entries, 144k host entries, 16k lpm entries.
- 3 96k l2 entries, 208k host entries, 16k lpm entries.
The default value is 2 (160k l2 entries, 144k host entries, 16k lpm entries).
- This command sets the single shareable forwarding table to option 2 that supports 160k L2 entries, 144k host entries, and 16k LPM entries.
switch(config)#platform trident forwarding-table partition 2 switch(config) - This command sets the single shareable forwarding table to option 3 that supports 96k L2 entries, 208k host entries, and 16k LPM entries. Since the switch was previously configured to option 2, you’ll see a warning notice before the changes are implemented.
#switch(config)#platform trident forwarding-table partition 3 Warning: StrataAgent will restart immediately
platform trident routing-table partition
The platform trident routing-table partition command manages the partition sizes for the hardware LPM table that stores IPv6 routes of varying sizes.
An IPv6 route of length /64 (or shorter) requires half the hardware resources of an IPv6 route that is longer than /64. The switch installs routes of varying lengths in different table partitions. This command specifies the size of these partitions to optimize table usage.
The no platform trident routing-table partition and default platform trident routing-table partition commands restore the default partitions sizes by removing the platform trident routing-table partition command from running-config.
Command Mode
Global Configuration
Command Syntax
platform trident routing-table partition SIZE
no platform trident routing-table partition
default platform trident routing-table partition
Parameters
- 1 16k IPv4 entries, 6k IPv6 (/64 and smaller) entries, 1k IPv6 (any prefix length).
- 2 16k IPv4 entries, 4k IPv6 (/64 and smaller) entries, 2k IPv6 (any prefix length).
- 3 16k IPv4 entries, 2k IPv6 (/64 and smaller) entries, 3k IPv6 (any prefix length).
The default value is 2 (16k IPv4 entries, 4k IPv6 (/64 and smaller) entries, 2k IPv6 (any prefix length).
Restrictions
Partition allocation cannot be changed from the default setting when uRPF is enabled for IPv6 traffic.
switch(config)#platform trident routing-table partition 1
switch(config)rib fib policy
The rib fib policy command enables FIB policy for a particular VRF under router general configuration mode.The FIB policy can be configured to advertise only specific RIB routes and exclude all other routes.
For example, a FIB policy can be configured that will not place routes associated with a specific origin in the routing table. These routes will not be used to forward data packets and these routes are not advertised by the routing protocol to neighbors.
The no rib fib policy and default rib fib policy commands restore the switch to its default state by removing the corresponding rib fib policy command from running-config .
Command Mode
Router General Configuration
Command Syntax
rib [ipv4 | ipv6] fib policy name
no rib [ipv4 | ipv6] fib policy name
default rib [ipv4 | ipv6] fib policy name
- ipv4 IPv4 configuration commands.
- ipv6 IPv6 configuration commands.
- name Route map name.
Switch(config)#router general
Switch(config-router-general)#vrf default
Switch(config-router-general-vrf-default)#rib ipv4 fib policy map1show arp
The show arp command displays all ARP tables. This command differs from the show ip arp command in that it shows MAC bindings for all protocols, whereas show ip arp only displays MAC address – IP address bindings. Addresses are displayed as their host name by including the resolve argument.
Command Mode
EXEC
show arp [VRF_INST][FORMAT][HOST_ADD][HOST_NAME][INTF][MAC_ADDR][DATA]
Parameters
- VRF_INST Specifies the VRF instance for which data is displayed.
- no parameter Context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
- FORMAT Displays format of host address. Options include:
- no parameter Entries associate hardware address with an IPv4 address.
- resolve Enter associate hardware address with a host name (if it exists).
- HOST_ADD IPv4 address by which routing table entries are filtered. Options include:
- no parameter Routing table entries are not filtered by host address.
- ipv4_addr Table entries matching specified IPv4 address.
- HOST_NAME Host name by which routing table entries are filtered. Options include:
- no parameter Routing table entries are not filtered by host name.
- host hostname Entries matching hostname (text).
- INTF Interfaces for which command displays status.
- no parameter Routing table entries are not filtered by interface.
- interface ethernet e_num Routed Ethernet interface specified by e_num.
- interface loopback l_num Routed loopback interface specified by l_num.
- interface management m_num Routed management interface specified by m_num.
- interface port-channel p_num Routed port channel Interface specified by p_num.
- interface vlan v_num VLAN interface specified by v_num.
- interface VXLAN vx_num VXLAN interface specified by vx_num.
- MAC_ADDR MAC address by which routing table entries are filtered. Options include:
- no parameter Routing table entries are not filtered by interface MAC address.
- mac_address mac_address Entries matching mac_address (dotted hex notation – H.H.H).
- DATA Detail of information provided by command. Options include:
- no parameter Routing table entries.
- summary Summary of ARP table entries.
- summary total Number of ARP table entries.
Related Commands
The cli vrf command specifies the context-active VRF.
switch>show arp
Address Age (min) Hardware Addr Interface
172.22.30.1 0 001c.730b.1d15 Management1
172.22.30.133 0 001c.7304.3906 Management1
switch>show dhcp server
Use the show dhcp server command to display DHCP server information.
Command Mode
EXEC
Command Syntax
show dhcp server [ipv4 | ipv6 | leases | vrf]
- ipv4 Displays details related to IPv4.
- ipv6 Displays details related to IPv6.
- leases Displays active leases.
- A.B.C.D/E IPv4 subnet.
- NAME Subnet name.
-
The following output displays DHCPv4.
switch#show dhcp server ipv4 IPv4 DHCP Server is active Debug log is enabled DNS server(s): 10.2.2.2 DNS domain name: mydomain Lease duration: 1 days 0 hours 0 minutes TFTP server: myserver (Option 66) 10.0.0.3 (Option 150) TFTP file: fileFoo Active Leases: 1 IPv4 DHCP interface status: Interface Status ------------------------------------------------- Ethernet1 Inactive (Could not determine VRF) Ethernet2 Inactive (Not in default VRF) Ethernet3 Inactive (Kernel interface not created yet) Ethernet4 Inactive (Not up) Ethernet5 Inactive (No IP address) Ethernet6 Active Vendor information: Vendor ID: default Sub-options Data ---------------- ---------------- 1 192.0.2.0, 192.0.2.1 Vendor ID: vendorFoo Sub-options Data ---------------- ----------- 2 192.0.2.2 3 “data” Subnet: 10.0.0.0/8 Subnet name: subnetFoo Range: 10.0.0.1 to 10.0.0.10 DNS server(s): 10.1.1.1 10.2.2.2 Lease duration: 3 days 3 hours 3 minutes Default gateway address: 10.0.0.3 TFTP server: subnetServerFoo (Option 66) 10.0.0.4 (Option 150) TFTP boot file: subnetFiletftp Active leases: 1 Reservations: MAC address: 1a1b.1c1d.1e1f IPv4 address: 10.0.0.1 MAC address: 2a2b.2c2d.2e2f IPv4 address: 10.0.0.2 -
In this example, DHCPv6 is configured with subnet fe80::/10 while being enabled on Ethernet1 with address fe80::1/64 and on Ethernet3 with address fe80::2/64.
switch#show dhcp server ipv6 IPv6 DHCP server is active Debug log is enabled DNS server(s): fe80::6 DNS domain name: testaristanetworks.com Lease duration: 1 days 3 hours 30 minutes Active leases: 0 IPv6 DHCP interface status: Interface Status --------------- ------ Ethernet1 Active Ethernet3 Active Subnet: fe80::/10 Subnet name: foo Range: fe80::1 to fe80::3 DNS server(s): fe80::4 fe80::5 Direct: Inactive (Multiple interfaces match this subnet: Ethernet1 Ethernet3) Relay: Active Active leases: 0 - This example illustrates when multiple subnets match an interface. In this example, DHCPv6 is configured with subnets fc00::/7 and fe80::/10 while being enabled on Ethernet1 with address fe80::1/10 and fc00::1/7.
switch#show dhcp server ipv6 IPv6 DHCP server is active DNS server(s): fc00::2 DNS domain name: testaristanetworks.com Lease duration: 1 days 3 hours 30 minutes Active leases: 0 IPv6 DHCP interface status: Interface Status --------------- ------ Ethernet1 Active Subnet: fc00::/7 Subnet name: data Range: fc00::1 to fc00::5 DNS server(s): fc00::6 fc00::8 Direct: Inactive (This and other subnets match interface Ethernet1) Relay: Active Active leases: 0 Subnet: fe80::/10 Subnet name: bar Direct: Inactive (This and other subnets match interface Ethernet1) Relay: Active Active leases: 0 - After disabling a subnet, the show dhcp server command displays the disable message with a reason. The number of active leases of the disabled subnets displays as0. In this example, there are overlapping subnets.
switch#show dhcp server IPv4 DHCP Server is active DNS server(s): 10.2.2.2 Lease duration: 1 days 0 hours 0 minutes Active Leases: 0 IPv4 DHCP interface status: Interface Status ------------------------------------------------- Ethernet1 Active Subnet: 10.0.0.0/24 (Subnet is disabled - overlapping subnet 10.0.0.0/8) Range: 10.0.0.1 to 10.0.0.10 DNS server(s): 10.3.3.3 10.4.4.4 Default gateway address: 10.0.0.4 Active leases: 0 Subnet: 10.0.0.0/8 (Subnet is disabled - overlapping subnet 10.0.0.0/24) DNS server(s): Default gateway address: 10.0.0.3 Active leases: 0 - In this example, the display output shows overlapping ranges.
switch#show dhcp server IPv4 DHCP Server is active DNS server(s): 10.2.2.2 Lease duration: 1 days 0 hours 0 minutes Active Leases: 0 IPv4 DHCP interface status: Interface Status ------------------------------------------------- Ethernet1 Active Subnet: 10.0.0.0/8 (Subnet is disabled - range 10.0.0.9-10.0.0.12 overlaps with an existing pool) Range: 10.0.0.1 to 10.0.0.10 Range: 10.0.0.9 to 10.0.0.12 DNS server(s): 10.3.3.3 10.4.4.4 Default gateway address: 10.0.0.4 Active leases: 0 - This example displays duplicate static IP address reservation.
Subnet: 10.0.0.0/8 (Subnet is disabled - ipv4-address 10.0.0.11 is reserved more than once) Subnet name: DNS server(s): Default gateway address: 10.0.0.3 Active leases: 0 Reservations: MAC address: 1a1b.1c1d.1e1f IPv4 address: 10.0.0.11 MAC address: 2a2b.2c2d.2e2f IPv4 address: 10.0.0.11 - Use the show dhcp server leases command to display detailed information about the IP addresses allocated by the DHCP Server (including the IP address, the expected end time for that address, the time when the address is handed out, and the equivalent MAC address).
switch#show dhcp server leases 10.0.0.10 End: 2019/06/20 17:44:34 UTC Last transaction: 2019/06/19 17:44:34 UTC MAC address: 5692.4c67.460a 2000:0:0:40::b End: 2019/06/20 18:06:33 UTC Last transaction: 2019/06/20 14:36:33 UTC MAC address: 165a.a86d.ffac
show dhcp server leases
Use the show dhcp server leases command to display DHCP server lease information.
Command Mode
EXEC
Command Syntax
show dhcp server leases [ ipv4 | ipv6
- ipv4 Displays details related to IPv4.
- ipv6 Displays details related to IPv6.
- leases Displays active leases.
- Use the show dhcp server leases command to display detailed information about the IP addresses allocated by the DHCP Server (including the IP address, the expected end time for that address, the time when the address is handed out, and the equivalent MAC address).
switch#show dhcp server leases 10.0.0.10 End: 2019/06/20 17:44:34 UTC Last transaction: 2019/06/19 17:44:34 UTC MAC address: 5692.4c67.460a 2000:0:0:40::b End: 2019/06/20 18:06:33 UTC Last transaction: 2019/06/20 14:36:33 UTC MAC address: 165a.a86d.ffac
show hardware capacity
The show hardware capacity command displays the utilization of the hardware resources:
Command Mode
Privileged EXEC
Command Syntax
show hardware capacity
Example
- The following command is used to show the utilization of the hardware resources:
switch#show hardware capacity Forwarding Resources Usage Table Feature Chip Used Used Free Committed Best Case High Entries (%) Entries Entries Max Watermark Entries ---------------- -------------------- --------------- ---------- ------- ---------- ------------ ------------ --------- ECMP 0 0% 4095 0 4095 0 ECMP Mpls 0 0% 4095 0 4095 0 ECMP Routing 0 0% 4095 0 4095 0 ECMP VXLANOverlay 0 0% 4095 0 4095 0 ECMP VXLANTunnel 0 0% 3891 0 3891 0
show interface tunnel
The show interface tunnel command displays the interface tunnel information.
Command Mode
EXEC
Command Syntax
show interface tunnel number
Parameter
number Specifies the tunnel interface number.
switch#show interface tunnel 10
Tunnel10 is up, line protocol is up (connected)
Hardware is Tunnel, address is 0a01.0101.0800
Internet address is 192.168.1.1/24
Broadcast address is 255.255.255.255
Tunnel source 10.1.1.1, destination 10.1.1.2
Tunnel protocol/transport GRE/IP
Key disabled, sequencing disabled
Checksumming of packets disabled
Tunnel TTL 10, Hardware forwarding enabled
Tunnel TOS 10
Path MTU Discovery
Tunnel transport MTU 1476 bytes
Up 3 seconds show ip
The show ip command displays IPv4 routing, IPv6 routing, IPv4 multicast routing, and VRRP status on the switch.
Command Mode
EXEC
Command Syntax
show ip
switch>show ip
IP Routing : Enabled
IP Multicast Routing : Disabled
VRRP: Configured on 0 interfaces
IPv6 Unicast Routing : Enabled
IPv6 ECMP Route support : False
IPv6 ECMP Route nexthop index: 5
IPv6 ECMP Route num prefix bits for nexthop index: 10
switch>show ip arp
The show ip arp command displays ARP cache entries that map an IPv4 address to a corresponding MAC address. The table displays addresses by their host names when the command includes the resolve argument.
Command Mode
EXEC
Command Syntax
show ip arp [VRF_INST][FORMAT][HOST_ADD][HOST_NAME][INTF][MAC_ADDR][DATA]
Parameters
- VRF_INST Specifies the VRF instance for which data is displayed.
- no parameter Context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
- FORMAT Displays format of host address. Options include:
- no parameter Entries associate hardware address with an IPv4 address.
- resolve Enter associate hardware address with a host name (if it exists).
- HOST_ADDR IPv4 address by which routing table entries are filtered. Options include:
- no parameter Routing table entries are not filtered by host address.
- ipv4_addr Table entries matching specified IPv4 address.
- HOST_NAME Host name by which routing table entries are filtered. Options include:
- no parameter Routing table entries are not filtered by host name.
- host hostname Entries matching hostname (text).
- INTERFACE_NAME Interfaces for which command displays status.
- no parameter Routing table entries are not filtered by interface.
- interface ethernet e_num Routed Ethernet interface specified by e_num.
- interface loopback l_num Routed loopback interface specified by l_num.
- interface management m_num Routed management interface specified by m_num.
- interface port-channel p_num Routed port channel Interface specified by p_num.
- interface vlan v_num VLAN interface specified by v_num.
- interface VXLAN vx_num VXLAN interface specified by vx_num.
- MAC_ADDR MAC address by which routing table entries are filtered. Options include:
- no parameter Routing table entries are not filtered by interface MAC address.
- mac_address mac_address entries matching mac_address (dotted hex notation – H.H.H).
- DATA Detail of information provided by command. Options include:
- no parameter Routing table entries.
- summary Summary of ARP table entries.
- summary total Number of ARP table entries.
Related Commands
The cli vrf command specifies the context-active VRF.
- This command displays ARP cache entries that map MAC addresses to IPv4 addresses.
switch>show ip arp Address Age (min) Hardware Addr Interface 172.25.0.2 0 004c.6211.021e Vlan101, Port-Channel2 172.22.0.1 0 004c.6214.3699 Vlan1000, Port-Channel1 172.22.0.2 0 004c.6219.a0f3 Vlan1000, Port-Channel1 172.22.0.3 0 0045.4942.a32c Vlan1000, Ethernet33 172.22.0.5 0 f012.3118.c09d Vlan1000, Port-Channel1 172.22.0.6 0 00e1.d11a.a1eb Vlan1000, Ethernet5 172.22.0.7 0 004f.e320.cd23 Vlan1000, Ethernet6 172.22.0.8 0 0032.48da.f9d9 Vlan1000, Ethernet37 172.22.0.9 0 0018.910a.1fc5 Vlan1000, Ethernet29 172.22.0.11 0 0056.cbe9.8510 Vlan1000, Ethernet26 switch> - This command displays ARP cache entries that map MAC addresses to IPv4 addresses. Host names assigned to IP addresses are displayed in place of the address.
switch>show ip arp resolve Address Age (min) Hardware Addr Interface green-vl101.new 0 004c.6211.021e Vlan101, Port-Channel2 172.22.0.1 0 004c.6214.3699 Vlan1000, Port-Channel1 orange-vl1000.n 0 004c.6219.a0f3 Vlan1000, Port-Channel1 172.22.0.3 0 0045.4942.a32c Vlan1000, Ethernet33 purple.newcompa 0 f012.3118.c09d Vlan1000, Port-Channel1 pink.newcompany 0 00e1.d11a.a1eb Vlan1000, Ethernet5 yellow.newcompa 0 004f.e320.cd23 Vlan1000, Ethernet6 172.22.0.8 0 0032.48da.f9d9 Vlan1000, Ethernet37 royalblue.newco 0 0018.910a.1fc5 Vlan1000, Ethernet29 172.22.0.11 0 0056.cbe9.8510 Vlan1000, Ethernet26 switch>
show ip arp inspection statistics
The show ip arp inspection statistics command displays the statistics of inspected ARP packets. For a VLAN specified, only VLANs with ARP inspection enabled will be displayed. If no VLAN is specified, all VLANs with ARP inspection enabled are displayed.
Command Mode
EXEC
Command Syntax
show ip arp inspection statistics [vlan [VID]|[INTERFACE] interface intf_slot | intf_port]
- VID Specifies the VLAN interface ID.
- INTERFACE Specifies the interface (e.g., Ethernet).
- intf_slot Interface slot.
- intf_port Interface port.
- INTF Specifies the VLAN interface slot and port.
- This command display statistics of inspected ARP packets for VLAN 10.
switch(config)#show ip arp inspection statistics vlan 10 Vlan : 10 -------------- ARP Req Forwarded = 20 ARP Res Forwarded = 20 ARP Req Dropped = 1 ARP Res Dropped = 1 Last invalid ARP: Time: 10:20:30 ( 5 minutes ago ) Reason: Bad IP/Mac match Received on: Ethernet 3/1 Packet: Source MAC: 00:01:00:01:00:01 Dest MAC: 00:02:00:02:00:02 ARP Type: Request ARP Sender MAC: 00:01:00:01:00:01 ARP Sender IP: 1.1.1 switch(config)# - This command displays ARP inspection statistics for Ethernet interface 3/1.
switch(config)#show ip arp inspection statistics ethernet interface 3/1 Interface : 3/1 -------- ARP Req Forwarded = 10 ARP Res Forwarded = 10 ARP Req Dropped = 1 ARP Res Dropped = 1 Last invalid ARP: Time: 10:20:30 ( 5 minutes ago ) Reason: Bad IP/Mac match Received on: VLAN 10 Packet: Source MAC: 00:01:00:01:00:01 Dest MAC: 00:02:00:02:00:02 ARP Type: Request ARP Sender MAC: 00:01:00:01:00:01 ARP Sender IP: 1.1.1 switch(config)#
show ip arp inspection vlan
The show ip arp inspection vlan command displays the configuration and operation state of ARP inspection. For a VLAN range specified, only VLANs with ARP inspection enabled will be displayed. If no VLAN is specified, all VLANs with ARP inspection enabled are displayed. The operation state turns to Active when hardware is ready to trap ARP packets for inspection.
Command Mode
EXEC
Command Syntax
show ip arp inspection vlan [LIST]
Parameters
LIST Specifies the VLAN interface number.
switch(config)#show ip arp inspection vlan 1 - 150
VLAN 1
----------
Configuration
: Enabled
Operation State : Active
VLAN 2
----------
Configuration
: Enabled
Operation State : Active
{...}
VLAN 150
----------
Configuration
: Enabled
Operation State : Active
switch(config)#show ip dhcp relay counters
The show ip dhcp relay counters command displays the number of DHCP packets received, forwarded, or dropped on the switch and on all interfaces enabled as DHCP relay agents.
Command Mode
EXEC
Command Syntax
show ip dhcp relay counters
switch>show ip dhcp relay counters
| Dhcp Packets |
Interface | Rcvd Fwdd Drop | Last Cleared
----------|----- ---- -----|---------------------
All Req | 376 376 0 | 4 days, 19:55:12 ago
All Resp | 277 277 0 |
| |
Vlan1000 | 0 0 0 | 4 days, 19:54:24 ago
Vlan1036 | 376 277 0 | 4 days, 19:54:24 ago
switch>show ip dhcp relay
The show ip dhcp relay command displays the DHCP relay agent configuration status on the switch.
Command Mode
EXEC
Command Syntax
show ip dhcp relay
switch>show ip dhcp relay
DHCP Relay is active
DHCP Relay Option 82 is disabled
DHCP Smart Relay is enabled
Interface: Vlan100
DHCP Smart Relay is disabled
DHCP servers: 10.4.4.4
switch>show ip dhcp snooping counters
The show ip dhcp snooping counters command displays counters that track the quantity of DHCP request and reply packets that the switch receives. Data is either presented for each VLAN or aggregated for all VLANs with counters for packets dropped.
Command Mode
EXEC
Command Syntax
show ip dhcp snooping counters [COUNTER_TYPE]
Parameters
- no parameter Command displays counters for each VLAN.
- debug Command displays aggregate counters and drop cause counters.
- This command displays the number of DHCP packets sent and received on each VLAN.
switch>show ip dhcp snooping counters | Dhcp Request Pkts | Dhcp Reply Pkts | Vlan | Rcvd Fwdd Drop | Rcvd Fwdd Drop | Last Cleared -----|------ ----- ------|----- ---- ------|------------- 100 | 0 0 0 | 0 0 0 | 0:35:39 ago switch> - This command displays the number of DHCP packets sent on the switch.
switch>show ip dhcp snooping counters debug Counter Snooping to Relay Relay to Snooping ----------------------------- ----------------- ----------------- Received 0 0 Forwarded 0 0 Dropped - Invalid VlanId 0 0 Dropped - Parse error 0 0 Dropped - Invalid Dhcp Optype 0 0 Dropped - Invalid Info Option 0 0 Dropped - Snooping disabled 0 0 Last Cleared: 3:37:18 ago switch>
show ip dhcp snooping hardware
The show ip dhcp snooping hardware command displays internal hardware DHCP snooping status on the switch.
Command Mode
EXEC
Command Syntax
show ip dhcp snooping hardware
This command DHCP snooping hardware status.
switch>show ip dhcp snooping hardware
DHCP Snooping is enabled
DHCP Snooping is enabled on following VLANs:
None
Vlans enabled per Slice
Slice: FixedSystem
None
switch>show ip dhcp snooping
The show ip dhcp snooping command displays the DHCP snooping configuration.
Command Mode
EXEC
Command Syntax
show ip dhcp snooping
- ip dhcp snooping globally enables DHCP snooping.
- ip dhcp snooping vlan enables DHCP snooping on specified VLANs.
- ip dhcp relay information option (Global) enables insertion of option-82 snooping data.
- ip helper-address enables the DHCP relay agent on a configuration mode interface.
switch>show ip dhcp snooping
DHCP Snooping is enabled
DHCP Snooping is operational
DHCP Snooping is configured on following VLANs:
100
DHCP Snooping is operational on following VLANs:
100
Insertion of Option-82 is enabled
Circuit-id format: Interface name:Vlan ID
Remote-id: 00:1c:73:1f:b4:38 (Switch MAC)
switch>show ip hardware fib summary
The show ip hardware fib summary command displays the statistics of the RECMP.
Command Mode
Privileged EXEC
Command Syntax
show ip hardware fib summary
Example
- The following command is used to show the statistics of RECMP:
switch#show ip hardware fib summary Fib summary ----------- Adjacency sharing: disabled BFD peer event: enabled Deletion Delay: 0 Protect default route: disabled PBR: supported URPF: supported ICMP unreachable: enabled Max Ale ECMP: 600 UCMP weight deviation: 0.0 Maximum number of routes: 0 Fib compression: disabled Resource optimization for adjacency programming: enabled Adjacency resource optimization thresholds: low 20, high 80About Output
- The last two lines of the output shows whether the feature is enabled and what are the corresponding threshold values for starting and stopping the optimization process.
show ip interface
- Interface description
- Internet address
- Broadcast address
- Address configuration method
- Proxy-ARP status
- MTU size
Command Mode
EXEC
Command Syntax
show ip interface [INTERFACE_NAME][VRF_INST]
- INTERFACE_NAME Interfaces for which command displays status.
- no parameter All routed interfaces.
- ipv4_addr Neighbor IPv4 address.
- ethernet e_range Routed Ethernet interfaces specified by e_range.
- loopback l_range Routed loopback interfaces specified by l_range.
- management m_range Routed management interfaces specified by m_range.
- port-channel p_range Routed port channel Interfaces specified by p_range.
- vlan v_range VLAN interfaces specified by v_range.
- VXLAN vx_range VXLAN interfaces specified by vx_range.
- VRF_INST Specifies the VRF instance for which data is displayed.
- no parameter Context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
- This command displays IP status of configured VLAN interfaces numbered between 900 and 910.
switch>show ip interface vlan 900-910 ! Some interfaces do not exist Vlan901 is up, line protocol is up (connected) Description: ar.pqt.mlag.peer Internet address is 170.23.254.1/30 Broadcast address is 255.255.255.255 Address determined by manual configuration Proxy-ARP is disabled MTU 9212 bytes Vlan903 is up, line protocol is up (connected) Description: ar.pqt.rn.170.23.254.16/29 Internet address is 170.23.254.19/29 Broadcast address is 255.255.255.255 Address determined by manual configuration Proxy-ARP is disabled MTU 9212 bytes - This command displays the configured TCP Maximum Segment Size (MSS) ceiling value of 1436 bytes for an Ethernet interface 25.
switch>show ip interface ethernet 25 Ethernet25 is up, line protocol is up (connected) Internet address is 10.1.1.1/24 Broadcast address is 255.255.255.255 IPv6 Interface Forwarding : None Proxy-ARP is disabled Local Proxy-ARP is disabled Gratuitous ARP is ignored IP MTU 1500 bytes IPv4 TCP MSS egress ceiling is 1436 bytes
show ip interface brief
- IP address
- Operational status
- Line protocol status
- MTU size
Command Mode
EXEC
Command Syntax
show ip interface [INTERFACE_NAME][VRF_INST] brief
- INTERFACE_NAME Interfaces for which command displays status.
- no parameter All routed interfaces.
- ipv4_addr Neighbor IPv4 address.
- ethernet e_range Routed Ethernet interfaces specified by e_range.
- loopback l_range Routed loopback interfaces specified by l_range.
- management m_range Routed management interfaces specified by m_range.
- port-channel p_range Routed port channel Interfaces specified by p_range.
- vlan v_range VLAN interfaces specified by v_range.
- VXLAN vx_range VXLAN interface range specified by vx_range.
- VRF_INST Specifies the VRF instance for which data is displayed.
- no parameter Context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
switch>show ip interface vlan 900-910 brief
! Some interfaces do not exist
Interface IP Address Status Protocol MTU
Vlan901 170.33.254.1/30 up up 9212
Vlan902 170.33.254.14/29 up up 9212
Vlan905 170.33.254.17/29 up up 1500
Vlan907 170.33.254.67/29 up up 9212
Vlan910 170.33.254.30/30 up up 9212show ip route
The show ip route command displays routing table entries that are in the Forwarding Information Base (FIB), including static routes, routes to directly connected networks, and dynamically learned routes. Multiple equal-cost paths to the same prefix are displayed contiguously as a block, with the destination prefix displayed only on the first line.
The show running-config command displays configured commands not in the FIB.
Command Mode
EXEC
Command Syntax
show ip route [VRF_INSTANCE][ADDRESS][ROUTE_TYPE][INFO_LEVEL][PREFIX]
Parameters
- VRF_INSTANCE Specifies the VRF instance for which data is displayed.
- no parameter Context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
- ADDRESS Filters routes by IPv4 address or subnet.
- no parameter All routing table entries.
- ipv4_addr Routing table entries matching specified address.
- ipv4_subnet Routing table entries matching specified subnet (CIDR or address-mask).
- ROUTE_TYPE Filters routes by specified protocol or origin. Options include:
- no parameter All routing table entries.
- aggregate Entries for BGP aggregate routes.
- bgp Entries added through BGP protocol.
- connected Entries for routes to networks directly connected to the switch.
- isis Entries added through ISIS protocol.
- kernel Entries appearing in Linux kernel but not added by eos software.
- ospf Entries added through OSPF protocol.
- rip Entries added through RIP protocol.
- static Entries added through CLI commands.
- vrf Displays routes in a VRF.
- INFO_LEVEL Filters entries by next hop connection. Options include:
- no parameter Filters routes whose next hops are directly connected.
- detail Displays all routes.
- PREFIX Filters routes by prefix.
- no parameter Specific route entry that matches the ADDRESS parameter.
- longer-prefixes All subnet route entries in range specified by ADDRESS parameter.
Related Commands
The cli vrf command specifies the context-active VRF.
- This command displays IPv4 routes learned through BGP.
switch>show ip route bgp Codes: C - connected, S - static, K - kernel, O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1, E2 - OSPF external type 2, N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type2, B I - iBGP, B E - eBGP, R - RIP, A - Aggregate B E 170.44.48.0/23 [20/0] via 170.44.254.78 B E 170.44.50.0/23 [20/0] via 170.44.254.78 B E 170.44.52.0/23 [20/0] via 170.44.254.78 B E 170.44.54.0/23 [20/0] via 170.44.254.78 B E 170.44.254.112/30 [20/0] via 170.44.254.78 B E 170.53.0.34/32 [1/0] via 170.44.254.78 B I 170.53.0.35/32 [1/0] via 170.44.254.2 via 170.44.254.13 via 170.44.254.20 via 170.44.254.67 via 170.44.254.35 via 170.44.254.98 - This command displays the unicast IP routes installed in the system.
switch#show ip route VRF name: default Codes: C - connected, S - static, K - kernel, O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1, E2 - OSPF external type 2, N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type2, B I - iBGP, B E - eBGP, R - RIP, I - ISIS, A B - BGP Aggregate, A O - OSPF Summary, NG - Nexthop Group Static Route Gateway of last resort is not set C 10.1.0.0/16 is directly connected, Vlan2659 C 10.2.0.0/16 is directly connected, Vlan2148 C 10.3.0.0/16 is directly connected, Vlan2700 S 172.17.0.0/16 [1/0] via 172.24.0.1, Management1 S 172.18.0.0/16 [1/0] via 172.24.0.1, Management1 S 172.19.0.0/16 [1/0] via 172.24.0.1, Management1 S 172.20.0.0/16 [1/0] via 172.24.0.1, Management1 S 172.22.0.0/16 [1/0] via 172.24.0.1, Management1 C 172.24.0.0/18 is directly connected, Management1 - This command displays the leaked routes from a source VRF.
switch#show ip route vrf VRF2 20.0.0.0/8 ... S L 20.0.0.0/8 [1/0] (source VRF VRF1) via 10.1.2.10, Ethernet1
- This example displays an IPv4 route with Forwarding Equivalency Class (FEC) with an IPv4 next hop and an IPv6 next hop route.
#show ip route 10.1.0.0/23 VRF: default Source Codes: C - connected, S - static, K - kernel, O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1, E2 - OSPF external type 2, N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type2, B - Other BGP Routes, B I - iBGP, B E - eBGP, R - RIP, I L1 - IS-IS level 1, I L2 - IS-IS level 2, O3 - OSPFv3, A B - BGP Aggregate, A O - OSPF Summary, NG - Nexthop Group Static Route, V - VXLAN Control Service, M - Martian, DH - DHCP client installed default route, DP - Dynamic Policy Route, L - VRF Leaked, G - gRIBI, RC - Route Cache Route, CL - CBF Leaked Route S 10.1.0.0/23 [1/0] via 2000:0:0:43::2, Ethernet2 via 10.0.1.2, Ethernet4
show ip route age
The show ip route age command displays the time when the route for the specified network was present in the routing table. It does not account for the changes in parameters like metric, next-hop etc.
Command Mode
EXEC
Command Syntax
show ip route ADDRESS age
Parameters
- ipv4_addr Routing table entries matching specified address.
- ipv4_subnet Routing table entries matching specified subnet (CIDR or address-mask).
switch>show ip route 172.17.0.0/20 age
Codes: C - connected, S - static, K - kernel,
O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1,
E2 - OSPF external type 2, N1 - OSPF NSSA external type 1,
N2 - OSPF NSSA external type2, B I - iBGP, B E - eBGP,
R - RIP, I - ISIS, A - Aggregate
B E 172.17.0.0/20 via 172.25.0.1, age 3d01h
switch>show ip route gateway
The show ip route gateway command displays IP addresses of all gateways (next hops) used by active routes.
Command Mode
EXEC
Command Syntax
show ip route [VRF_INSTANCE] gateway
Parameters
- no parameter Context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
Related Commands
The cli vrf command specifies the context-active VRF.
switch>show ip route gateway
The following gateways are in use:
172.25.0.1 Vlan101
172.17.253.2 Vlan3000
172.17.254.2 Vlan3901
172.17.254.11 Vlan3902
172.17.254.13 Vlan3902
172.17.254.17 Vlan3903
172.17.254.20 Vlan3903
172.17.254.66 Vlan3908
172.17.254.67 Vlan3908
172.17.254.68 Vlan3908
172.17.254.29 Vlan3910
172.17.254.33 Vlan3911
172.17.254.35 Vlan3911
172.17.254.105 Vlan3912
172.17.254.86 Vlan3984
172.17.254.98 Vlan3992
172.17.254.99 Vlan3992
switch>show ip route host
- F static routes from the FIB.
- R routes defined because the IP address is an interface address.
- B broadcast address.
- A routes to any neighboring host for which the switch has an ARP entry.
Command Mode
EXEC
Command Syntax
show ip route [VRF_INSTANCE] host
Parameters
- no parameter Context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
Related Commands
The cli vrf command specifies the context-active VRF.
switch>show ip route host
R - receive B - broadcast F - FIB, A - attached
F 127.0.0.1 to cpu
B 172.17.252.0 to cpu
A 172.17.253.2 on Vlan2000
R 172.17.253.3 to cpu
A 172.17.253.10 on Vlan2000
B 172.17.253.255 to cpu
B 172.17.254.0 to cpu
R 172.17.254.1 to cpu
B 172.17.254.3 to cpu
B 172.17.254.8 to cpu
A 172.17.254.11 on Vlan2902
R 172.17.254.12 to cpu
F 172.26.0.28 via 172.17.254.20 on Vlan3003
via 172.17.254.67 on Vlan3008
via 172.17.254.98 on Vlan3492
via 172.17.254.2 on Vlan3601
via 172.17.254.13 on Vlan3602
via 172.17.253.2 on Vlan3000
F 172.26.0.29 via 172.25.0.1 on Vlan101
F 172.26.0.30 via 172.17.254.29 on Vlan3910
F 172.26.0.32 via 172.17.254.105 on Vlan3912
switch>show ip route match tag
The show ip route match tag command displays the route tag assigned to the specified IPv4 address or subnet. Route tags are added to static routes for use by route maps.
Command Mode
EXEC
Command Syntax
show ip route [VRF_INSTANCE] ADDRESS match tag
- VRF_INSTANCE Specifies the VRF instance for which data is displayed.
- no parameter Context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
- ADDRESS Displays routes of specified IPv4 address or subnet.
- ipv4_addr Routing table entries matching specified IPv4 address.
- ipv4_subnet Routing table entries matching specified IPv4 subnet (CIDR or address-mask).
switch>show ip route 172.17.50.0/23 match tag
Codes: C - connected, S - static, K - kernel,
O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1,
E2 - OSPF external type 2, N1 - OSPF NSSA external type 1,
N2 - OSPF NSSA external type2, B I - iBGP, B E - eBGP,
R - RIP, I L1 - IS-IS level 1, I L2 - IS-IS level 2,
O3 - OSPFv3, A B - BGP Aggregate, A O - OSPF Summary,
NG - Nexthop Group Static Route, V - VXLAN Control Service,
DH - DHCP client installed default route, M - Martian
O E2 172.17.50.0/23 tag 0
switch>show ip route summary
The show ip route summary command displays the number of routes, categorized by destination prefix, in the routing table.
Command Mode
EXEC
Command Syntax
show ip route [VRF_INSTANCE] summary Parameters
- no parameter Context-active VRF.
- vrf vrf_name Specifies name of VRF instance. System default VRF is specified by default.
switch>show ip route summary
Route Source Number Of Routes
-------------------------------------
connected 15
static 0
ospf 74
Intra-area: 32 Inter-area:33 External-1:0 External-2:9
NSSA External-1:0 NSSA External-2:0
bgp 7
External: 6 Internal: 1
internal 45
attached 18
aggregate 0
switch>show ip verify source
The show ip verify source command displays the IP source guard (IPSG) configuration, operational states, and IP-MAC binding entries for the configuration mode interface.
Command Mode
EXEC
Command Syntax
show ip verify source [VLAN | DETAIL]
- VLAN Displays all VLANs configured in no ip verify source vlan.
- DETAIL Displays all source IP-MAC binding entries configured for IPSG.
- This command verifies the IPSG configuration and operational states.
switch(config)#show ip verify source Interface Operational State --------------- ------------------------ Ethernet1 IP source guard enabled Ethernet2 IP source guard disabled - This command displays all VLANs configured in no ip verify source vlan. Hardware programming errors, e.g.,VLAN classification failed, are indicated in the operational state. If an error occurs, this VLAN will be considered as enabled for IPSG. Traffic on this VLAN will still be filtered by IPSG.
switch(config)#show ip verify source vlan IPSG disabled on VLANS: 1-2 VLAN Operational State --------------- ------------------------ 1 IP source guard disabled 2 Error: vlan classification failed - This command displays all source IP-MAC binding entries configured for IPSG. A source binding entry is considered active if it is programmed in hardware. IP traffic matching any active binding entry will be permitted. If a source binding entry is configured on an interface or a VLAN whose operational state is IPSG disabled, this entry will not be installed in the hardware, in which case an “IP source guard disabled” state will be shown. If a port channel has no member port configured, binding entries configured for this port channel will not be installed in hardware, and a “Port-Channel down” state will be shown.
switch(config)#show ip verify source detail Interface IP Address MAC Address VLAN State -------------- ----------- --------------- ----- ------------------------ Ethernet1 10.1.1.1 0000.aaaa.1111 5 active Ethernet1 10.1.1.5 0000.aaaa.5555 1 IP source guard disabled Port-Channel1 20.1.1.1 0000.bbbb.1111 4 Port-Channel down
show platform arad ip route summary
The show platform arad ip route summary command shows hardware resource usage of IPv4 routes.
Command Mode
EXEC
Command Syntax
show platform arad ip route summary
- The agent SandL3Unicast terminate command enables restarting the layer 3 agent to ensure IPv4 routes are optimized.
- The ip hardware fib optimize command enables IPv4 route scale.
- The show platform arad ip route command shows resources for all IPv4 routes in hardware. Routes that use the additional hardware resources will appear with an asterisk.
switch(config)#show platform arad ip route summary
Total number of VRFs: 1
Total number of routes: 25
Total number of route-paths: 21
Total number of lem-routes: 4
switch(config)#show platform arad ip route
The show platform arad ip route command shows resources for all IPv4 routes in hardware. Routes that use the additional hardware resources will appear with an asterisk.
Command Mode
EXEC
Command Syntax
show platform arad ip route
- This command displays the platform unicast forwarding routes. In this example, the ACL label field in the following table is 4094 by default for all routes. If an IPv4 egress RACL is applied to an SVI, all routes corresponding to that VLAN will have an ACL label value. In this case, the ACL Label field value is 2.
switch#show platform arad ip route Tunnel Type: M(mpls), G(gre) ------------------------------------------------------------------------------- | Routing Table | | |------------------------------------------------------------------------------ |VRF| Destination | | | | Acl | | ECMP| FEC | Tunnel | ID| Subnet | Cmd | Destination | VID | Label | MAC / CPU Code |Index|Index|T Value ------------------------------------------------------------------------------- |0 |0.0.0.0/8 |TRAP | CoppSystemL3DstMiss|0 | - | ArpTrap | - |1031 | - |0 |10.1.0.0/16 |TRAP | CoppSystemL3DstMiss|2659 | - | ArpTrap | - |1030 | - |0 |10.2.0.0/16 |TRAP | CoppSystemL3DstMiss|2148 | - | ArpTrap | - |1026 | - |0 |172.24.0.0/18 |TRAP | CoppSystemL3DstMiss|0 | - | ArpTrap | - |1032 | - |0 |0.0.0.0/0 |TRAP | CoppSystemL3LpmOver|0 | - | SlowReceive | - |1024 | - |0 |10.1.0.0/32* |TRAP | CoppSystemIpBcast |0 | - | BcastReceive | - |1027 | - |0 |10.1.0.1/32* |TRAP | CoppSystemIpUcast |0 | - | Receive | - |32766| - |0 |10.1.255.1/32* |ROUTE| Po1 |2659 |4094 | 00:1f:5d:6b:ce:45 | - |1035 | - |0 |10.1.255.255/32* |TRAP | CoppSystemIpBcast |0 | - | BcastReceive | - |1027 | - |0 |10.3.0.0/32* |TRAP | CoppSystemIpBcast |0 | - | BcastReceive | - |1027 | - |0 |10.3.0.1/32* |TRAP | CoppSystemIpUcast |0 | - | Receive | - |32766| - |0 |10.3.255.1/32* |ROUTE| Et18 |2700 |2 | 00:1f:5d:6b:00:01 | - |1038 | - ........................................................... - Related Commands
- The agent SandL3Unicast terminate command enables restarting the Layer 3 agent to ensure IPv4 routes are optimized.
- The ip hardware fib optimize command enables IPv4 route scale.
- The show platform arad ip route summary command shows hardware resource usage of IPv4 routes.
- This command shows resources for all IPv4 routes in hardware. Routes that use the additional hardware resources will appear with an asterisk.
switch(config)#show platform arad ip route Tunnel Type: M(mpls), G(gre) * - Routes in LEM ------------------------------------------------------------------------------- | Routing Table | | |------------------------------------------------------------------------------ |VRF| Destination | | | |Acl | |ECMP | FEC | Tunnel |ID | Subnet | Cmd | Destination |VID |Label| MAC / CPU Code |Index|Index|T Value ------------------------------------------------------------------------------- |0 |0.0.0.0/8 |TRAP |CoppSystemL3DstMiss|0 | - |ArpTrap | - |1030 | - |0 |100.1.0.0/32 |TRAP |CoppSystemIpBcast |0 | - |BcastReceive | - |1032 | - |0 |100.1.0.0/32 |TRAP |CoppSystemIpUcast |0 | - |Receive | - |32766| - |0 |100.1.255.255/32|TRAP |CoppSystemIpBcast |0 | - |BcastReceive | - |1032 | - |0 |200.1.255.255/32|TRAP |CoppSystemIpBcast |0 | - |BcastReceive | - |1032 | - |0 |200.1.0.0/16 |TRAP |CoppSystemL3DstMiss|1007| - |ArpTrap | - |1029 | - |0 |0.0.0.0/0 |TRAP |CoppSystemL3LpmOver|0 | - |SlowReceive | - |1024 | - |0 |4.4.4.0/24* |ROUTE|Et10 |1007| - |00:01:00:02:00:03| - |1033 | - |0 |10.20.30.0/24* |ROUTE|Et9 |1006| - |00:01:00:02:00:03| - |1027 | - switch(config)#
show platform barefoot bfrt
The show platform barefoot bfrt command displays information about the current BfRuntime server configuration.
Command Mode
EXEC
Command Syntax
show platform barefoot bfrt
Parameters
no parameter state of the system.
Example
(switch)#show platform barefoot bfrt
Namespace: management
FixedSystem:0.0.0.0:50052show platform fap eedb ip-tunnel gre interface tunnel
The show platform fap eedb ip-tunnel gre interface tunnel command verifies the tunnel encapsulation programming for the tunnel interface.
Command Mode
EXEC
Command Syntax
show platform fap eedb ip-tunnel gre interface tunnel number
Parameter
number Specifies the tunnel interface number.
switch#show platform fap eedb ip-tunnel gre interface tunnel 10
----------------------------------------------------------------------------
| Jericho0 |
| GRE Tunnel Egress Encapsulation DB
|
|--------------------------------------------------------------------------|
| Bank/ | OutLIF | Next | VSI | Encap | TOS | TTL | Source | Destination|
OamLIF| OutLIF | Drop|
| Offset| | OutLIF | LSB | Mode | | | IP | IP | Set
| Profile| |
|--------------------------------------------------------------------------|
| 3/0 | 0x6000 | 0x4010 | 0 | 2 | 10 | 10 | 10.1.1.1 | 10.1.1.2 | No
| 0 | No |
switch#show platform fap eedb ip-tunnel
-------------------------------------------------------------------------------
| Jericho0 |
| IP Tunnel Egress Encapsulation DB
|
|------------------------------------------------------------------------------
| Bank/ | OutLIF | Next | VSI | Encap| TOS | TTL | Src | Destination | OamLIF
| OutLIF | Drop|
| Offset| | OutLIF | LSB | Mode | Idx | Idx | Idx | IP | Set |
Profile | |
|------------------------------------------------------------------------------
| 3/0 | 0x6000 | 0x4010 | 0 | 2 | 9 | 0 | 0 | 10.1.1.2 | No |
0 | No |show platform fap tcam summary
The show platform fap tcam summary command displays information about the TCAM bank that is allocated for GRE packet termination lookup.
Command Mode
EXEC
Command Syntax
show platform fap tcam summary
switch# show platform fap tcam summary
Tcam Allocation (Jericho0)
Bank Used By Reserved By
---------- ----------------------- -----------
0 dbGreTunnel -show platform trident forwarding-table partition
The show platform trident forwarding-table partition command displays the size of the L2 MAC entry tables, L3 IP forwarding tables, and Longest Prefix Match (LPM) routes.
Command Mode
Privileged EXEC
Command Syntax
show platform trident forwarding-table partition
show platform trident forwarding-table partition flexible
switch(config)# show platform trident forwarding-table partition
L2 Table Size: 96k
L3 Host Table Size: 208k
LPM Table Size: 16k
switch(config)#switch(config)# show platform trident forwarding-table partition flexible
--------------------------------------------------
Minimum L2 entries = 32768
Minimum L3 entries = 16384
Maximum L2 entries = 262144
Maximum L3 entries = 262144
Maximum Exact Match entries = 131072
L2 entries per bucket = 4
L3 entries per bucket = 4
Exact Match entries per bucket = 2
Maximum entries per bucket = 4
Maximum shared buckets = 65536
Maximum entries per bank = 32768
Maximum shared banks = 8
ALPM entries per bank = 46080
ALPM = Enabled
--------------------
# UFT bank details #
--------------------
S - Shared UFT bank, D - Dedicated UFT bank
+-------------+------------+------+------------+--------------+
| Physical ID | Feature | Type | Logical ID | Hash Offset |
+-------------+------------+------+------------+--------------+
| 0 | L2 | D | 0 | 0x4 |
| 1 | L2 | D | 1 | 0xe |
| 2 | ALPM | S | N/A | 0 |
| 3 | ALPM | S | N/A | 0 |
| 4 | ALPM | S | N/A | 0 |
| 5 | ALPM | S | N/A | 0 |
| 6 | L2 | S | 2 | 0xc |
| 7 | ExactMatch | S | 0 | 0xc |
| 8 | ExactMatch | S | 1 | 0xf |
| 9 | L3 | S | 2 | 0xc |
| 10 | L3 | D | 0 | 0x0 |
| 11 | L3 | D | 1 | 0x8 |
+-------------+------------+------+------------+--------------+show rib route ip
The show rib route ip command displays a list of IPv4 Routing Information Base (RIB) routes.
Command Mode
EXEC
Command Syntax
show rib route ip [vrf vrf_name][PREFIX][ROUTE TYPE]
- vrf vrf_name Displays RIB routes from the specified VRF.
- PREFIX dDisplays routes filtered by the specified IPv4 information. Options include:
- ip_address Displays RIB routes filtered by the specified IPv4 address.
- ip_subnet_mask Displays RIB routes filtered by the specified IPv4 address and subnet mask.
- ip_prefix Displays RIB routes filtered by the specified IPv4 prefix.
- ROUTE TYPE Displays routes filtered by the specified route type. Options include:
- bgp Displays RIB routes filtered by BGP.
- connected Displays RIB routes filtered by connected routes.
- dynamicPolicy Displays RIB routes filtered by dynamic policy routes.
- host Displays RIB routes filtered by host routes.
- isis Displays RIB routes filtered by ISIS routes.
- ospf Displays RIB routes filtered by OSPF routes.
- ospf3 Displays RIB routes filtered by OSPF3 routes.
- reserved Displays RIB routes filtered by reserved routes.
- route-input Displays RIB routes filtered by route-input routes.
- static Displays RIB routes filtered by static routes.
- vrf Displays routes in a VRF.
- vrf-leak Displays leaked routes in a VRF.
- This command displays IPv4 RIB static routes.
switch# show rib route ip static VRF name: default, VRF ID: 0xfe, Protocol: static Codes: C - Connected, S - Static, P - Route Input B - BGP, O - Ospf, O3 - Ospf3, I - Isis > - Best Route, * - Unresolved Nexthop L - Part of a recursive route resolution loop >S 10.80.0.0/12 [1/0] via 172.30.149.129 [0/1] via Management1, directly connected >S 172.16.0.0/12 [1/0] via 172.30.149.129 [0/1] via Management1, directly connected switch# - This command displays IPv4 RIB connected routes.
switch# show rib route ip connected VRF name: default, VRF ID: 0xfe, Protocol: connected Codes: C - Connected, S - Static, P - Route Input B - BGP, O - Ospf, O3 - Ospf3, I - Isis > - Best Route, * - Unresolved Nexthop L - Part of a recursive route resolution loop >C 10.1.0.0/24 [0/1] via 10.1.0.102, Ethernet1 >C 10.2.0.0/24 [0/1] via 10.2.0.102, Ethernet2 >C 10.3.0.0/24 [0/1] via 10.3.0.102, Ethernet3 switch# - This command displays routes leaked through VRF leak agent.
switch# show rib route ip vrf VRF2 vrf-leak VRF: VRF2, Protocol: vrf-leak ... >VL 20.0.0.0/8 [1/0] source VRF: VRF1 via 10.1.2.10 [0/0] type ipv4 via 10.1.2.10, Ethernet1
show rib route fib policy excluded
The show rib route fib policy excluded command displays the RIB routes filtered by FIB policy. The fib policy excluded option displays the RIB routes that have been excluded from being programmed into FIB, by FIB policy.
Command Mode
EXEC
Command Syntax
show rib route [ipv4 | ipv6] fib policy excluded
switch# show rib route ipv6 fib policy excluded
switch# show rib route ip bgp fib policy excluded
VRF name: default, VRF ID: 0xfe, Protocol: bgp
Codes: C - Connected, S - Static, P - Route Input
B - BGP, O - Ospf, O3 - Ospf3, I - Isis
> - Best Route, * - Unresolved Nexthop
L - Part of a recursive route resolution loop
>B 10.1.0.0/24 [200/0]
via 10.2.2.1 [115/20] type tunnel
via 10.3.5.1, Ethernet1
via 10.2.0.1 [115/20] type tunnel
via 10.3.4.1, Ethernet2
via 10.3.6.1, Ethernet3
>B 10.1.0.0/24 [200/0]
via 10.2.2.1 [115/20] type tunnel
via 10.3.5.1, Ethernet1
via 10.2.0.1 [115/20] type tunnel
via 10.3.4.1, Ethernet2
via 10.3.6.1, Ethernet3show rib route summary
The show rib route summary command displays information about the routes present in the Routing Information Base.
Command Mode
EXEC
Command Syntax
show rib route summary [INFO_LEVEL]
- no parameter variable displays data in one table with the summary of all routes in the RIB for default VRF.
- brief keyword displays one table with the summary of all routes across all configured VRFs.
- ip keyword displays one table with the summary of all IPv4 in the RIB for default VRF.
- ipv6 keyword displays one table with the summary of all IPv4 in the RIB for default VRF.
- vrf vrf_Name keyword displays one table with the summary of all routes in the Routing Information Base for the specified VRF.
- vrf all keyword displays one table with the summary of all routes in the Routing Information Base for each configured VRF.
- INFO_LEVEL amount of information that is displayed. Options include:
- Display Values
- VRF VRF RIB displayed.
- Route Source Source for the route.
- Number of Routes Number of routes for each source.
- Display Values
-
The following displays data in one table with the summary of all routes in the RIB for default VRF.
switch> show rib route summary VRF: default Route Source Number Of Routes -------------------- ---------------- BGP 1 Connected 4 Dynamic policy 0 IS-IS 0 OSPF 0 OSPFv3 0 RIP 0 Route input 2 Static 0 VRF leak 0 -
The following displays data in one table with the summary of all routes across all configured VRFs.
switch> show rib route summary brief Route Source Number Of Routes -------------------- ---------------- BGP 2 Connected 8 Dynamic policy 0 IS-IS 0 OSPF 0 OSPFv3 0 RIP 0 Route input 4 Static 0 VRF leak 0 -
The following displays data in one table with the summary of all IPv4 routes in the RIB for default VRF.
switch> show rib route summary ip VRF: default Route Source Number Of Routes -------------------- ---------------- BGP 1 Connected 4 Dynamic policy 0 IS-IS 0 OSPF 0 OSPFv3 0 RIP 0 Route input 2 Static 0 VRF leak 0 -
The following displays data in one table with the summary of all IPv6 routes in the RIB for default VRF.
switch> show rib route summary ipv6 VRF: default Route Source Number Of Routes -------------------- ---------------- BGP 0 Connected 0 Dynamic policy 0 IS-IS 0 OSPF 0 OSPFv3 0 RIP 0 Route input 0 Static 0 VRF leak 0 -
The following displays data in one table with the summary of all routes in the RIB for the VRF named red.
switch> show rib route summary vrf red VRF: red Route Source Number Of Routes -------------------- ---------------- BGP 1 Connected 4 Dynamic policy 0 IS-IS 0 OSPF 0 OSPFv3 0 RIP 0 Route input 2 Static 0 VRF leak 0 -
The following displays data in one table with the summary of all routes in the RIB for each configured VRF.
switch> show rib route summary vrf all VRF: red Route Source Number Of Routes -------------------- ---------------- BGP 1 Connected 4 Dynamic policy 0 IS-IS 0 OSPF 0 OSPFv3 0 RIP 0 Route input 2 Static 0 VRF leak 0 VRF: default Route Source Number Of Routes -------------------- ---------------- BGP 1 Connected 4 Dynamic policy 0 IS-IS 0 OSPF 0 OSPFv3 0 RIP 0 Route input 2 Static 0 VRF leak 0
show routing-context vrf
The show routing-context vrf command displays the context-active VRF. The context-active VRF determines the default VRF that VRF-context aware commands use when displaying routing table data from a specified VRF.
Command Mode
EXEC
Command Syntax
show routing-context vrf
Related Commands
The cli vrf command specifies the context-active VRF.
switch> show routing-context vrf
Current VRF routing-context is PURPLE
switch>show tunnel fib static interface gre
The show tunnel fib static interface gre command displays the Forwarding Information Base (FIB) information for a static interface GRE tunnel.
Command Mode
EXEC
Command Syntax
show tunnel fib static interface gre number
Parameter
number Specifies the tunnel index number.
switch# show tunnel fib static interface gre 10
Type 'Static Interface', index 10, forwarding Primary
via 10.6.1.2, 'Ethernet6/1'
GRE, destination 10.1.1.2, source 10.1.1.1, ttl 10, tos 0xashow vrf
The show vrf command displays the VRF name, RD, supported protocols, state and included interfaces for the specified VRF or for all VRFs on the switch.
Command Mode
EXEC
Command Syntax
show vrf [VRF_INSTANCE]
Parameters
- no parameter Information is displayed for all VRFs.
- vrf vrf_name Information is displayed for the specified user-defined VRF.
switch> show vrf purple
Vrf RD Protocols State Interfaces
-------- ----------- ---------- ----------- --------------
purple 64496:237 ipv4 no routing Vlan42, Vlan43
switch>tcp mss ceiling
The tcp mss ceiling command configures the Maximum Segment Size (MSS) limit in the TCP header on the configuration mode interface and enables TCP MSS clamping.
The no tcp mss ceiling and the default tcp mss ceiling commands remove any MSS ceiling limit previously configured on the interface.
Command Mode
Interface-Ethernet Configuration
Subinterface-Ethernet Configuration
Interface-Port-channel Configuration
Subinterface-Port-channel Configuration
Interface-Tunnel Configuration
Interface-VLAN Configuration
Command Syntax
tcp mss ceiling {ipv4 segment size | ipv6 segment size}{egress | ingress}
no tcp mss ceiling
default tcp mss ceiling
- ipv4 segment size The IPv4 segment size value in bytes. Values range from 64 to 65515.
- ipv6 segment size The IPv6 segment size value in bytes. Values range from 64 to 65495. This option is not supported on Sand platform switches (Qumran-MX, Qumran-AX, Jericho, Jericho+).
- egress The TCP SYN packets that are forwarded from the interface to the network.
- ingress The TCP SYN packets that are received from the network to the interface. Not supported on Sand platform switches.
- On Sand platform switches (Qumran-MX, Qumran-AX, Jericho, Jericho+), this command works only for egress, and is supported only on IPv4 unicast packets entering the switch.
- Clamping can only be configured in one direction per interface and works only on egress on Sand platform switches.
- To configure ceilings for both IPv4 and IPv6 packets, both configurations must be included in a single command; re-issuing the command overwrites any previous settings.
- Clamping configuration has no effect on GRE transit packets.
switch(config)# interface ethernet 5
switch(config-if-Et5)# no switchport
switch(config-if-Et5)# tcp mss ceiling ipv4 1458 egress
switch(config-if-Et5)#tunnel
The tunnel command configures options for protocol-over-protocol tunneling. Because interface-tunnel configuration mode is not a group change mode, running-config is changed immediately after commands are executed. The exit command does not affect the configuration.
The no tunnel command deletes the specified tunnel configuration.
Command Mode
Interface-tunnel Configuration
Command Syntax
tunnel options
no tunnel options
- options Specifies the various tunneling options as listed below.
- destination Destination address of the tunnel.
- ipsec Secures the tunnel with the IPsec address.
- key Sets the tunnel key.
- mode Tunnel encapsulation method.
- path-mtu-discovery Enables the Path MTU discovery on tunnel.
- source Source of the tunnel packets.
- tos Sets the IP type of service value.
- ttl Sets time to live value.
- underlay Tunnel underlay.
switch(config)# ip routing
switch(config)# interface Tunnel 10
switch(config-if-Tu10)# tunnel mode gre
switch(config-if-Tu10)# ip address 192.168.1.1/24
switch(config-if-Tu10)# tunnel source 10.1.1.1
switch(config-if-Tu10)# tunnel destination 10.1.1.2
switch(config-if-Tu10)# tunnel path-mtu-discovery
switch(config-if-Tu10)# tunnel tos 10
switch(config-if-Tu10)# tunnel ttl 10vrf (Interface mode)
The vrf command adds the configuration mode interface to the specified VRF. You must create the VRF first, using the vrf instance command.
The no vrf and default vrf commands remove the configuration mode interface from the specified VRF by deleting the corresponding vrf command from running-config.
All forms of the vrf command remove all IP addresses associated with the configuration mode interface.
Command Mode
Interface-Ethernet Configuration
Interface-Loopback Configuration
Interface-Management Configuration
Interface-Port-channel Configuration
Interface-VLAN Configuration
Command Syntax
vrf [vrf_name]
no vrf [vrf_name]
default vrf [vrf_name]
Parameters
vrf_name Name of configured VRF.
- These commands add the configuration mode interface (vlan 20) to the VRF named purple.
switch(config)# interface vlan 20 switch(config-if-Vl20)# vrf purple switch(config-if-Vl20)# - These commands remove the configuration mode interface from VRF purple.
switch(config)# interface vlan 20 switch(config-if-Vl20)# no vrf purple switch(config-if-Vl20)#
vrf instance
The vrf instance command places the switch in VRF configuration mode for the specified VRF. If the named VRF does not exist, this command creates it. The number of user-defined VRFs supported varies by platform.
To add an interface to the VRF once it is created, use the vrf (Interface mode) command.
The no vrf instance and default vrf instance commands delete the specified VRF instance by removing the corresponding vrf instance command from running-config. This also removes all IP addresses associated with interfaces that belong to the deleted VRF.
The exit command returns the switch to global configuration mode.
Command Mode
Global Configuration
Command Syntax
vrf instance [vrf_name]
no vrf instance [vrf_name]
default vrf instance [vrf_name]
Parameters
vrf_name Name of VRF being created, deleted or configured. The names main and default are reserved.
switch(config)# vrf instance purple
switch(config-vrf-purple)#