Multicast Source Discovery Protocol (MSDP)

Multicast Source Discovery Protocol (MSDP) describes a topology that connects multiple IPv4 Protocol Independent Multicast Sparse-Mode (PIM-SM) domains. Each PIM-SM domain uses its independent Rendezvous Point (RP) without depending on RPs in other domains.

These sections describe the Arista MSDP implementation.

MSDP Introduction
MSDP Description
MSDP Configuration
MSDP Commands

MSDP Introduction

Arista switches support the following MSDP features:

Basic MSDP speaker functions
MSDP peer configuration - description, connect-source interface, keepalive time, and hold time.
ACL filtering of inbound and outbound Source-Active (SA) messages.
Mesh groups.
Displaying peer status.
Displaying filtered SA messages received from MSDP peers.

MSDP does not support the following:

Configuring PIM-SM Anycast-RP (RFC4610) and MSDP on the same platform. Instead, choose either MSDP Anycast RP orPIM-SM Anycast-RP as the implementation on your network.

MSDP Description

The Multicast Source Discovery Protocol (MSDP) defines a topology connecting Protocol Independent Multicast sparse mode (PIM-SM) domains.

MSDP provides inter-domain access to multicast sources in all domains by enabling all Rendezvous Points (RPs) to discover multicast sources outside of their domains. RPs also use MSDP to announce sources that are sending to a multicast group.

MSDP Speakers
Network Configuration
MSDP Exchange Processes

MSDP Speakers

An MSDP speaker is a router in a PIM-SM domain that has MSDP peering sessions with MSDP peers in other domains. An MSDP peering session is a TCP connection through which peers exchange MSDP control information. An MSDP peer is a router that is connected to the speaker through a peering session.

PIM uses MSDP to register a local source with remote domain RPs through Source Active (SA) messages, which originate at the local domain’s RP. Receivers in remote PIM-SM domains depend only on RPs in their domains to learn of multicast data sources in other domains. Multicast data is subsequently delivered from a source to receivers in different domains through a PIM-SM source tree.

MSDP Speaker Configuration describes the process of configuring MSDP speakers.

Network Configuration

The TCP connections between RPs are defined either through an underlying unicast routing table or by configuring a default MSDP peer. A typical MSDP configuration utilizes a BGP specified routing table. SA messages are MSDP control messages that peers exchange during peering sessions.

Source Active Messages
Reverse Path Forwarding
Default MSDP Peers

Source Active Messages

A Source Active (SA) message is a message that an RP creates and sends to MSDP peers when it learns of a new multicast source through a PIM register message. RPs that intend to originate or receive SA messages must establish MSDP peering with other RPs, either directly or through intermediate MSDP peers. An RP that is not a DR on a shared network should only originate SAs in response to register messages it receives from the DR. It does not originate SA's for directly connected sources in its domain.

SA messages contain the following fields:

Source address of the data source.
Group address that receives data sent by the source.
IP address of the RP.

Th SA Cache is the repository of SA messages received by the MSDP speaker. The switch always stores received SA messages. Managing the SA Cache describes procedures that limit the size of the SA cache and options for displaying the cache.

Reverse Path Forwarding

Reverse Path Forwarding (RPF) is a multicast packet transport technique that ensures loop-free packet forwarding by using a router’s unicast routing table. Traffic forwarding is based on source addresses instead of destination addresses. RPF is implemented as defined in RFC 3618.

Packet forwarding is based on the packet’s unicast reverse path. An RPF router prevents network loops by only forwarding a packet when it enters through the interface holding its source routing entry.

When a multicast packet enters a router's interface, the router checks the reverse path of the packet by examining the list of networks that are reachable through the input interface. If the list contains a matching routing entry for the multicast packet’s source IP address, the packet is forwarded to all other interfaces that are participants in the multicast group. Otherwise, the packet is dropped.

RPF requires that the unicast routing table is correct and converged. It also assumes that the use of symmetric forward and reverse paths between router and sender. RPF fails on uni-directional links.

Displaying RPF Peers describes commands that display RPF peers.

Default MSDP Peers

The default peer is the MSDP peer from which the MSDP speaker accepts SA messages. If there is only one MSDP peer, all of its SA messages will be accepted. When multiple default peers are configured the switch uses the first default peer to appear in the running-config. Default MSDP peers invalidate the use of RPF over unicast routing tables.

Each default peer may be associated with a prefix list. The prefix list specifies the RPs from where the speaker accepts SA messages. When the running-config contains multiple default peers with prefix lists, an SA is accepted from the first default peer in the running-config whose prefix list contains the RP in the SA. The speaker accepts all remaining SAs from the first default peer that is not associated with a prefix list.

Configuring the Default Peer describes commands that configure default peers.

Control Information Exchange

An RP originates an SA message when a source registers with the RP to send data to a multicast group. RPs periodically originate SA messages while its registered sources send data to maintain messages in SA caches of its MSDP peers. RPs that have no registered sources periodically send keepalive messages to maintain TCP connections with its peers.

MSDP defines the following timers that specify the transmission frequency of control messages:

SA Advertisement Time: Duration of SA Advertisement intervals. An RP sends periodic SA messages to reference each registered source once per interval. SA advertisement time is 60 seconds.
Keepalive Time: Period between the transmission of consecutive keepalive messages. Default keepalive time is 60 seconds. Minimum keepalive time is one second.
Hold Timer: Period an MSDP speaker maintains a peer TCP connection after receiving an SA or keepalive message from the peer. Default time is 75 seconds. Minimum hold time is three seconds.

MSDP Data Exchange

This sequence describes the exchange of multicast data across PIM domains through MSDP:

When a source’s first data packet is registered by the first hop router, the RP extracts the data from the packet and forwards it down the shared tree in the PIM domain.
The RP informs MSDP peers of the new source by sending a Source-Active (SA) message that identifies the source, the recipient group, and the RP’s address or originator ID.
Upon receiving the SA message, an MSDP peer which is the RP for a multicast tree that includes members interested in the multicast sends a PIM join message (S,G) toward the data source.
After the RP on another domain joins the PIM Designated Router (DR) in the first domain, multicast data traffic flows natively over the multicast tree to the second domain's RP.
If the source times out, this process repeats when the source goes active again.

MSDP Configuration

These sections describe the configuration of the switch as an MSDP speaker and the establishment of MSDP peering sessions.

MSDP Speaker Configuration
Establishing MSDP Peers
MSDP Network Configuration
Managing the SA Cache
Configuring MSDP in a non-default VRF

MSDP requires that TCP port 639 (MSDP) is open on the control plane. The default control-plane ACL includes a permit rule that allows TCP packets access through the MSDP port.

MSDP Speaker Configuration

The switch is configured as an MSDP speaker when MSDP is enabled. MSDP is enabled by configuring an MSDP peer. Configuring an MSDP Peer describes the process of configuring an MSDP peer.

Source-Address (SA) messages that an MSDP speaker originates contain the speaker’s Rendezvous Point (RP) address, as configured through PIM statements and processes. MSDP provides a method of assigning an originator ID address, which the speaker uses in place of its RP address when advertising SA messages. The originator-id local-interface command configures the switch to set the RP address to the specified interface’s IP address in SA messages that it originates as an MSDP speaker.

Only RPs originate SA messages and only for its registered sources. RPs do not originate periodic SA messages for sources in other PIM domains. MSDP speakers that are not RPs do not originate periodic SA messages. Intermediate MSDP speakers forward SA messages received from other domains. Intermediate speakers are not required to be RPs.

Example

These commands configure the switch to use the IP address assigned to interface loopback 100 as the RP address in SA messages that it originates.

switch(config)# router msdp
switch (config-router-msdp)# originator-id local-interface loopback 100
switch (config-router-msdp)#

Establishing MSDP Peers

These sections describe MSDP Peer configuration tasks.

Configuring an MSDP Peer
Mesh Groups
Filtering SA Messages
Keep-alive, Hold Time, and Reset Time Configuration
Displaying Peer Information

Configuring an MSDP Peer

The switch attempts to establish MSDP peering sessions through IP addresses configured as MSDP peers. The peer command configures a specified address as an MSDP peer and enables the switch as an MSDP speaker if no other peers are configured. The peering session with the device at the specified network is established over a TCP connection. The local-interface command can be used to specify an interface through which the switch establishes the TCP session. When no interface is specified, the connection is established through an interface determined by existing routing algorithms.

To display MSDP peer information, enter show ip msdp peer .

Example

These commands assign an IP address to loopback interface 100, then configure 10.4.4.12 as an MSDP peer and establish the TCP peer session through the loopback.

switch(config)# interface loopback 100
switch(config-if-Lo100)# ip address 10.6.8.6/24
switch(config-if-Lo100)# exit
switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# local-interface loopback 100
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Connection status:
   State: Connect
   Resets: 0
   Connection Source: Loopback100 ( 10.6.8.6 )
SAs accepted:
switch(config-router-msdp-peer-10.4.4.12)#

To associate descriptive text with the specified MSDP peer, use the description (MSDP) command.

Example

These commands associate the string NORTH with the MSDP peer located at 10.4.4.12.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# description NORTH
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Description: NORTH
Connection status:
   State: Connect
   Resets: 0
   Connection Source: Loopback100 (10.6.8.6)
SAs accepted:
switch(config-router-msdp-peer-10.4.4.12)#

To close the peering session with the specified MSDP peer, use the disabled (MSDP) command. This terminates the TCP connection between the switch and the peer. The peer remains configured and the peer session can be resumed by removing the disabled command from running-config.

Examples

This command closes the peering session with the MSDP peer at 10.4.4.12.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# disabled
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Description: NORTH
Connection status:
   State: Disbled
   Resets: 0
   Connection Source: Loopback100 ( 10.6.8.6 )
SAs accepted:
switch(config-router-msdp-peer-10.4.4.12)#

This command reopens the peering session with the peer at 10.4.4.12.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# no disabled
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Description: NORTH
Connection status:
   State: Connect
   Resets: 0
   Connection Source: Loopback100 ( 10.6.8.6 )
SAs accepted:
switch(config-router-msdp-peer-10.4.4.12)#

Mesh Groups

Each node in a fully meshed network is directly connected to every other node in the network. Each peer in a fully meshed MSDP speaker network can be configured as a member of a mesh group. SA messages received from a mesh group peer are not forwarded to other members of the mesh group.

To configure an MSDP peer connection as an MSDP mesh group member, use the mesh-group command. An MSDP peer can be assigned to multiple mesh groups. Multiple peer connections can be assigned to the same mesh group.

Note: Peer-specific mesh-group configuration is performed in Router MSDP Peer Configuration or Router MSDP Peer VRF Configuration Mode. To remove all configured connections from a mesh group, use the no mesh-group command in Router MSDP Configuration Mode.

To display the mesh group membership of configured MSDP peers, enter show msdp mesh-group.

Example

These commands configure the MSDP peer connection to 10.1.1.14 as a member of the AREA-1 mesh group, then displays members of mesh groups to which configured MSDP peers belong.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.1.1.14
switch(config-router-msdp-peer-10.1.1.14)# mesh-group AREA-1
switch(config-router-msdp-peer-10.1.1.14)# show msdp mesh-group
Mesh Group: AREA-1
        10.1.1.14
Mesh Group: tier_01
        10.24.18.13
Mesh Group: tier_02
        10.26.101.18
switch(config-router-msdp-peer-10.1.1.14)#

Filtering SA Messages

The switch can filter Source-Active (SA) messages that it sends and receives with Access Control Lists (ACLs). The commands accept standard and extended ACLs. The address field in standard ACLs filters an SA message on its multicast source address.

The sa-filter in command assigns an ACL to filter inbound SA messages from the MSDP peer connection being configured. The switch only accepts SA messages from the peer that pass the ACL. The switch accepts all SA messages from peers that are not assigned an input ACL. A peer can be assigned only one input filter ACL. Subsequent sa-filter in commands for a peer replace the existing command.

The sa-filter out command assigns an ACL as a filter for outbound SA messages to the MSDP peer connection being configured. The switch only sends SA messages to the peer that pass the ACL. The switch sends all specified SA messages to peers not assigned an output filter ACL. A peer can be assigned only one output ACL. Subsequent sa-filter out commands for a peer replace the existing command.

Example

These commands assign the IP ACLs named LIST-IN as the inbound SA message filter and LIST-OUT as the outbound SA message filter for the MSDP peer connection to 10.4.4.12.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# sa-filter in list LIST-IN
switch(config-router-msdp-peer-10.4.4.12)# sa-filter out list LIST-OUT
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Connection status:
   State: Listen
   Connection Source: Loopback100 (10.6.8.6)
SA Filtering:
Input Filter: LIST-IN
Output Filter: LIST-OUT
switch(config-router-msdp-peer-10.4.4.12)#

Keep-alive, Hold Time, and Reset Time Configuration

To configure the MSDP keep-alive and hold time intervals for a specified MSDP peer connection, use the keepalive (MSDP) command.

Keep-alive time interval is the period between the transmission of consecutive keep-alive messages. The default keep-alive time interval is 60 seconds.
Hold time interval is the period the switch waits for a KEEPALIVE or UPDATE message before it disables peering. The default hold time interval is 75 seconds.

The hold time interval must be longer than or equal to the keep-alive time interval.

Example

This command sets the keep-alive time to 45 seconds and the hold time to 80 seconds for the MSDP peer connection to 10.4.4.12.

switch(config)# router msdp
switch(config-router-msdp) #peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# keepalive 45 80
switch(config-router-msdp-peer-10.4.4.12)#

To specify the period that the switch waits after an MSDP peering session is reset before attempting to reestablish the session, enter connection retry interval. The default period is 30 seconds.

Example

This command configures the switch to wait 45 seconds after an MSDP peering session is reset before attempting to reestablish the session.

switch(config)# router msdp
switch(config-router-msdp)# connection retry interval 45
switch(config-router-msdp)#

To enable the encapsulation of multicast data packets on the sending MSDP peer and the decapsulation and forwarding of register packets on the receiving MSDP peer, use the forward register-packets command. The default is to not forward the data encapsulated in PIM register messages.

Example

This command enables the forwarding of encapsulated register packets.

switch(config)#router msdp
switch(config-router-msdp)#forward register-packets
switch(config-router-msdp)#

Displaying Peer Information

To display the MSDP peers, enter show ip msdp summary. The command also displays the operational status of each peer and the number of messages from the peers in the SA cache.

Example

This command displays the configured peers, the status of the peers, and the number of SA messages received from those peers.

switch(config)# show ip msdp summary
MSDP Peer Status Summary
Peer Address      State   SA Count 
192.168.3.18      Up      0        
192.168.3.16      Up      0        
192.168.3.37      Listen  0        
192.168.3.46      Up      0        
192.168.3.47      Up      0

MSDP Network Configuration

Displaying RPF Peers
Configuring the Default Peer

Displaying RPF Peers

The switch uses the unicast routing table to define TCP connections between RPs by selecting the next hop peer toward the originating RP of an SA message as the Reverse Path Forwarding (RPF) peer. The switch forwards SA messages that it receives from the RPF peer to all other MSDP peers. The switch rejects SA messages that it receives from non-RPF peers.

To display MSDP information for the peer from which the switch accepts SA messages for a specified Rendezvous Point (RP), enter show msdp rpf-peer.

Example

This command displays MSDP information for the peer from which the switch accepts SA messages for the RP at 10.5.29.4.

switch(config)# show msdp rpf-peer 10.5.29.4
Rpf Peer is 10.5.29.4 for RP 10.5.29.4

Configuring the Default Peer

The default peer is the MSDP peer from which the MSDP speaker is configured to accept all SA messages. A default peer may be associated with a prefix list. The prefix list specifies the RPs from where the speaker accepts SA messages.

The switch can designate multiple default peers:

Switch defines one peer: A default peer statement is not required; the switch accepts SA traffic from the configured peer.
Switch defines one default peer (no prefix list): The switch accepts all SA messages from only the default peer.
Switch defines multiple default peers (no prefix lists): The switch accepts all SA messages from only the first default peer listed in running-config. Other listed default peers take effect only if the peer named in the first default-peer statement is not accessible.
First default-peer statement includes a prefix list: The switch accepts all SA messages from the default peer whose originating RP is covered in the prefix list. The disposition of SA messages originating from other RPs is determined by subsequent default-peer statements.

To configure the specified MSDP peer connection as a default peer on the switch, use the default-peer command. The default peer address must be a previously configured MSDP peer (configured using the peer command).

Example

These commands configure an MSDP default peer.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.5.2.2
switch(config-router-msdp-peer-10.5.2.2)# default-peer
switch(config-router-msdp-peer-10.5.2.2)#

Managing the SA Cache

The switch stores Source Active (SA) messages after forwarding the information. This allows new group members to learn about the source before the next SA message is received. The caching action is not configurable and cannot be disabled.

SA messages have an expiration period of 90 seconds and remain in the SA cache until they expire. A peer’s SA limit defines the number of SA messages the switch stores from the peer. The switch does not store SA messages from a peer whose SA limit is reached until its cached messages start expiring.

Limiting SA Cache Contents
Displaying SA Cache Contents
Verifying Consistency Between the SA Cache and the Routing Table

Limiting SA Cache Contents

To configure the maximum number of SA messages from a specified MSDP peer that the switch stores in the SA cache, use the sa-limit command. The default limit of SA messages that the switch can store from a specified peer is 40000.

Example

This command sets the SA limit of 500 for the MSDP peer at 10.1.1.5.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.1.1.5
switch(config-router-msdp-peer-10.1.1.5)# sa-limit 500
switch(config-router-msdp-peer-10.1.1.5)#

The maximum number of SA messages that the switch can store in the SA cache for a specified multicast group address is configured by the group-limit command. The default limit of SA messages that the switch can store from a specified group is 40000.

Example

This command sets the maximum number of 1000 SAs for multicast group 225.13.15.8/29.

switch(config)# router msdp
switch(config-router-msdp)# group-limit 1000 source 225.13.15.8/29

The maximum number of rejected SA messages that the switch can store in the SA cache is configured by the ip msdp rejected-limit command. The default limit of rejected SA messages that the switch can store is 40000.

Example

This command sets 5000 as the maximum number of rejected SAs that the SA cache can contain.

switch(config)# router msdp
switch(config-router-msdp)# ip msdp rejected-limit 5000

Contents of the SA message cache are removed by the clear ip msdp sa-cache command. The command provides options for removing all cache contents or only contents of a specific multicast group.

Example

This command deletes all SA message cache contents.

switch(config)# router msdp
switch(config-router-msdp)# clear ip msdp sa-cache

Displaying SA Cache Contents

SA message cache contents are displayed by the show ip msdp sa-cache command. Filter options provided by the command for displaying partial cache contents include:

multicast group address: multicast group
source address and group address

The command can also display unexpired SAs rejected by ACL filters or cache limit exceeded conditions.

Example

This command displays the contents of the SA message cache.

switch(config)# show ip msdp sa-cache
MSDP Source Active Cache
(10.61.71.29, 234.1.4.2), RP 10.5.29.4, heard from 10.5.29.4
(10.51.71.23, 234.1.4.1), RP 10.5.29.4, heard from 10.5.29.4
(10.53.71.27, 234.1.4.2), RP 10.3.25.4, heard from 10.3.25.4
(10.10.101.24, 234.1.4.1), RP 10.2.44.4, heard from 10.2.44.4
(10.10.151.22, 234.1.4.1), RP 10.1.12.4, heard from 10.1.12.4

Information about specified MSDP peers, including SAs accepted from the peer is displayed by the show ip msdp peer command.

Example

This command displays data for the peer at 10.2.42.4, including SAs accepted from the peer.

switch(config)# show ip msdp peer 10.2.42.4 accepted-sas
MSDP Peer 10.2.42.4
Connection status:
  State: Up
  Connection Source: Loopback4 (10.2.43.4)
SA Filtering:
Input Filter: allow-multicast-for-msdp
Output Filter: allow-multicast-for-msdp
SAs accepted:
(10.62.79.30, 234.1.4.2), RP 10.2.42.4
(10.61.79.29, 234.1.4.1), RP 10.2.42.4
(10.62.79.30, 234.1.4.1), RP 10.2.42.4

The SA cache for the local PIM domain is displayed by the show ip msdp pim sa-cache command.

Example

This command displays the SA cache for the local PIM domain.

switch(config)# show ip msdp pim sa-cache
MSDP Source Active Messages for local Pim RP
(10.51.71.23, 234.1.4.1), RP 10.2.43.4
(10.20.91.26, 234.1.4.1), RP 10.2.43.4
(10.20.91.26, 234.1.4.2), RP 10.2.43.4
(10.20.91.24, 234.1.4.1), RP 10.2.43.4

Verifying Consistency Between the SA Cache and the Routing Table

To check the consistency between the multicast routing table and the MSDP Source-Address (SA) caches, enter show ip msdp sanity. When the command detects inconsistencies, it displays the cache entries that are not in the table.

Example

This command displays a sanity check that detects inconsistencies between the SA cache and the multicast routing table.

switch(config)# show ip msdp sanity
PIM SA cache entries not in the MRT
Msdp-learnt MRT entries not in the SA cache
SA cache entries not in the MRT
(192.168.3.8, 224.1.154.1)
(192.168.3.35, 224.1.167.1)
(192.168.3.16, 224.1.226.1)
(192.168.3.12, 224.1.182.1)
(192.168.3.33, 224.1.150.1)
May-Notify-MSDP entries not in the PIM SA cache
(need not be an error condition)
4.1), RP 10.2.42.4

Configuring MSDP in a non-default VRF

The MSDP can also be configured in a non-default VRF, when the default VRF used does not have a name. The following commands configure MSDP in a non-default VRF.

Example

These commands configure MSDP peer 1.1.1.1 in a non-default VRF blue.

switch(config)# router msdp
switch(config-router-msdp)# vrf blue
switch(config-router-msdp-vrf-blue)# peer 1.1.1.1

MSDP Commands

clear ip msdp sa-cache

The clear ip msdp sa-cache command removes contents of the Source-Active (SA) message cache. The command provides these filter options for removing partial cache contents:

contents of a multicast group by specifying its group address.
all cache contents.

Command Mode

Router MSDP Configuration

Router MSDP VRF Configuration

Command Syntax

clear ip msdp sa-cache [ADDRESS_FILTER]

Parameters

ADDRESS_FILTER IPv4 address used to select table entries for removal.

no parameter All SA messages.
grp_addr Multicast group address (IPv4 address). The grp_addr must be a valid multicast address.

Example

This command deletes all SA message cache contents.

switch(config)# router msdp
switch(config-router-msdp)# clear ip msdp sa-cache

connection retry interval

The connection retry interval command specifies the period that the switch waits after an MSDP peering session is reset before trying to reestablish the session. The default period is 30 seconds.

The no connection retry interval and default connection retry interval commands reset the timer interval to the default period of 30 seconds by removing the connection retry interval command from running-config.

Command Mode

Router MSDP Configuration

Router MSDP VRF Configuration

Command Syntax

connection retry interval connect_retry

no connection retry interval connect_retry

default connection retry interval connect_retry

Parameter

connect_retry Reconnect period (seconds). Value ranges from 1 to 65535. Default is 30.

Example

This command configures the switch to wait 45 seconds after an MSDP peering session is reset before attempting to reestablish the session.

switch(config)# router msdp
switch(config-router-msdp)# connection retry interval 45

default-peer

The default-peer command configures the specified MSDP peer connection as a default peer on the switch. The default peer configuration defines the peers from which the switch accepts Source-Active (SA) messages. When the command includes a prefix list parameter, the specified peer is the default peer for only SA messages originating from rendezvous points (RPs) covered by prefix list entries. The default peer address must be a previously configured MSDP peer (configured using the peer command).

Default peers provide an alternative to Reverse Packet Forwarding (RPF) typically used by MSDP to specify the peers from which a switch accepts SA messages. However, RPF requires a unicast routing table that is correct and converged. RPF also assumes symmetric forward and reverse paths between router and sender. RPF fails on uni-directional links. Default MSDP peers invalidate the use of RPF over unicast routing tables.

The switch can designate multiple default peers:

Switch defines one peer: A default peer statement is not required; the switch accepts SA traffic from the configured peer.
Switch defines one default peer (no prefix list): The switch accepts all SA messages from only the default peer.
Switch defines multiple default peers (no prefix lists): The switch accepts all SA messages from only the first default peer listed in running-config. Other listed default peers are used only when peers listed before them in running-config are not accessible.
First default-peer statement includes a prefix list: The switch accepts all SA messages from the default peer whose originating RP is covered in the prefix list. The disposition of SA messages originating from other RPs is determined by subsequent default-peer statements.

The no default-peer and default default-peer commands remove the corresponding default-peer command from running-config.

Command Mode

Router MSDP Peer Configuration

Router MSDP Peer VRF Configuration

Command Syntax

default-peer [PREFIX]

no default-peer

default default-peer

Parameters

PREFIX List of RPs from the SA messages originate for whiich the default peer is valid.

no parameter default peer is valid for SAs from all originating RPs.
prefix-list list_name name of the prefix list that defines affected originating RP prefixes.

Example

These commands configure two MSDP peers and configure the peer at 10.5.2.2 as the default peer.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.6.2.2
switch(config-router-msdp-peer-10.6.2.2)# exit
switch(config-router-msdp)# peer 10.5.2.2
switch(config-router-msdp-peer-10.5.2.2)# default-peer
switch(config-router-msdp-peer-10.5.2.2)#

description (MSDP)

The description command associates descriptive text with the configuration-mode MSDP peer.

The no description and default description commands remove the text association from the specified peer.

Command Mode

Router MSDP Peer Configuration

Router MSDP Peer VRF Configuration

Command Syntax

description description_string

no description

default description

Parameters

description_string text string that is associated with the peer.

Example

These commands associate the string NORTH with the MSDP peer located at 10.4.4.12.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# description NORTH
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Description: NORTH
Connection status:
   State: Connect
   Resets: 0
   Connection Source: Loopback100 (10.6.8.6)
SAs accepted:
switch(config-router-msdp-peer-10.4.4.12)#

disabled (MSDP)

The disabled command closes the peering session with the specified MSDP peer by terminating the TCP connection between the switch and the peer. The connection is not resumed until the shutdown command is removed from running-config.

The no disabled and default disabled commands establish an MSDP peering session with the specified peer by removing the corresponding disabled command from running-config.

Command Mode

Router MSDP Peer Configuration

Router MSDP Peer VRF Configuration

Command Syntax

disabled

no disabled

default disabled

Examples

This command closes the peering session with the MSDP peer at 10.4.4.12.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# disabled
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Description: NORTH
Connection status:
   State: Disbled
   Resets: 0
   Connection Source: Loopback100 ( 10.6.8.6 )
SAs accepted:
switch(config-router-msdp-peer-10.4.4.12)#

This command reopens the peering session with the peer at 10.4.4.12.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# no disabled
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Description: NORTH
Connection status:
   State: Connect
   Resets: 0
   Connection Source: Loopback100 ( 10.6.8.6 )
SAs accepted:
switch(config-router-msdp-peer-10.4.4.12)#

forward register-packets (MSDP)

The forward register-packets command enables the encapsulation of multicast data packets on the sending MSDP peer and the decapsulation and forwarding on a receiving MSDP peer.

The no forward register-packets and default forward register-packets commands disable this feature.

Command Mode

Router MSDP Configuration

Command Syntax

forward register-packets

no forward register-packets

default forward register-packets

Example

This command enables the encapsulation and forwarding of MSDP data packets.

switch(config)#router msdp
switch(config-router-msdp)#forward register-packets
switch(config-router-msdp)#

group-limit

The group-limit command specifies the maximum number of Source-Active (SA) messages that the switch allows in the SA cache for a specified multicast group address.

SA messages have an expiration period of 90 seconds and remain in the SA cache until they expire. The switch does not accept SA messages for a group whose cache limit is reached until its cached messages start expiring.

The no group-limit and default group-limit command removes the maximum group limit for the specified prefix by removing the corresponding group-limit statement from running-config.

Command Mode

Router MSDP Configuration

Router MSDP VRF Configuration

Command Syntax

group-limit quantity sourcesrc_subnet

no group-limit quantity source src_subnet

default group-limit quantity source src_subnet

Parameters

quantity maximum number of groups that can access the interface. Value ranges from 1 to 40000.
src_subnet Source IPv4 subnet (CIDR or address-mask notation).

Example

This command sets the maximum number of 1000 SAs for multicast group 10.13.15.8/29.

switch(config)# router msdp
switch(config-router-msdp)# group-limit 1000 source 10.13.15.8/29

ip msdp rejected-limit

The ip msdp rejected-limit command specifies the maximum number of rejected Source-Active messages that the switch allows in the SA cache.

SA messages have an expiration period of 90 seconds. They remain in the SA cache during this time. The default limit of rejected SA messages that the switch can store is 40000.

The no ip msdp rejected-limit and default ip msdp rejected-limit commands restore the rejected SA limit of 40000 by removing the ip msdp rejected-limit statement from running-config.

Command Mode

Router MSDP Configuration

Router MSDP VRF Configuration

Command Syntax

ip msdp rejected-limit quantity

no ip msdp rejected-limit

default ip msdp rejected-limit

Parameter

quantity maximum rejected SA messages the SA cache can store. Value ranges from 0 to 40000.

Example

This command sets 5000 as the maximum number of rejected SAs that the SA cache can contain.

switch(config)# router msdp
switch(config-router-msdp)# ip msdp rejected-limit 5000

keepalive (MSDP)

The keepalive command configures the MSDP keep-alive and hold time intervals for a specified MSDP peer connection.

Keep-alive time interval is the period between the transmission of consecutive keep-alive messages. The default keep-alive time interval is 60 seconds.
Hold time interval is the period the switch waits for a KEEPALIVE or UPDATE message before it disables peering. The default hold time interval is 75 seconds.

The no keepalive and default keepalive commands restore the default keep-alive and hold time intervals for the specified MSDP peer connection by removing the corresponding keepalive command from running-config.

Command Mode

Router MSDP Peer Configuration

Router MSDP Peer VRF Configuration

Command Syntax

keepalive keep_alive hold_time

no keepalive

default keepalive

Parameters

keep_alive keep-alive period in seconds. Value ranges from 1 to 65535. Default value is 60.
hold_time hold time in seconds. Value ranges from 1 to 65535. Default value is 75.
Note: The hold time interval must be longer than or equal to the keep-alive time interval.

Example

This command sets the keep-alive time to 45 seconds and the hold time to 80 seconds for the connection with the MSDP peer at 10.4.4.12.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# keepalive 45 80
switch(config-router-msdp-peer-10.4.4.12)#

local-interface

MSDP peering sessions are established over a TCP connection. The local-interface command specifies the interface through which the TCP connection is established with the configuration-mode MSDP peer. When the local-interface command is not used to specify an interface, the connection is established through an interface determined by existing routing algorithms.

The no local-interface and default local-interface commands remove the corresponding local-interface command from running-config, returning selection of the connecting interface to the routing algorithm.

Command Mode

Router MSDP Peer Configuration

Router MSDP VRF Peer Configuration

Command Syntax

local-interface interface

no local-interface

default local-interface

Parameters

interface local interface through which the TCP connection is established. Options include:

ethernet e_num Ethernet interface.
loopback l_num Loopback interface.
management m_num Management interface.
port-channel p_num Port-Channel Interface.
vlan v_num VLAN interface.
VXLAN vx_num VXLAN interface.

Example

These commands assign an IP address to interface loopback 100, then establish the TCP peer session to the MSDP peer at 10.4.4.12 through the loopback in the default VRF.

switch(config)# interface loopback 100
switch(config-if-Lo100)# ip address 10.6.8.6/24
switch(config-if-Lo100)# exit
switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# local-interface loopback 100
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Connection status:
   State: Connect
   Resets: 0
   Connection Source: Loopback100 (10.6.8.6)
SAs accepted:
switch(config-router-msdp-peer-10.4.4.12)#

mesh-group

The mesh-groupcommand configures the configuration-mode MSDP peer connection as an MSDP mesh group member. A peer can be assigned to multiple mesh groups. Multiple MSDP peers can be assigned to a common mesh group.

An MSDP mesh group is a network of MSDP speakers where each speaker directly connects to every other speaker. The switch does not forward Source-Active (SA) messages that it receives from a mesh group peer to other peers of the same group.

The no mesh-group and default mesh-group commands delete the configuration-mode peer connection from a mesh group by removing the corresponding mesh-group command from running-config when issued in the router msdp peer configuration or the router msdp peer vrf configuration mode.

Note: To delete all configured connections from a specified mesh group, use the no mesh-group command in Router MSDP Configuration mode.

Command Mode

Router MSDP Configuration

Router MSDP Peer Configuration

Router MSDP Peer VRF Configuration

Command Syntax

mesh-group group_name

no mesh-group group_name

default mesh-group group_name

Parameters

group_name name of mesh group.

Related Command

show msdp mesh-group .

Examples

These commands configure the MSDP peer connection to 10.1.1.14 as a member of the AREA-1 mesh group, then display members of mesh groups to which configured MSDP peers belong.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.1.1.14
switch(config-router-msdp-peer-10.1.1.14)# mesh-group AREA-1
switch(config-router-msdp-peer-10.1.1.14)# show msdp mesh-group
Mesh Group: AREA-1
        10.1.1.14
Mesh Group: tier_01
        10.24.18.13
Mesh Group: tier_02
        10.26.101.18
switch(config-router-msdp-peer-10.1.1.14)#

These commands delete all configured connections from the AREA-1 mesh group.

switch(config)# router msdp
switch(config-router-msdp)# no mesh-group AREA-1
switch(config-router-msdp)#

originator-id local-interface

The originator-id local-interface command configures an originator ID to replace the Rendezvous Point (RP) address in Source-Address (SA) messages that it originates as an MSDP speaker.

SA messages that an MSDP speaker originates contain the speaker’s rendezvous point (RP) address, as configured through PIM statements and processes. An originator ID is an alternative IPv4 address that a speaker uses in place of its RP address when advertising SA messages. This command configures the switch to use the specified interface’s IP address as the RP address in SA messages that it originates.

The no originator-id local-interface and default originator-id local-interface commands configure the switch to use its RP address in SA messages that it sends by removing the originator-id local-interface command from running-config.

Command Mode

Router MSDP Configuration

Router MSDP VRF Configuration

Command Syntax

originator-id local-interface INTERFACE

no originator-id local-interface INTERFACE

default originator-id local-interface INTERFACE

Parameters

INTERFACE Specifies the interface from which the IP address is derived. Options include:

ethernet e_num Ethernet interface.
loopback l_num Loopback interface.
management m_num Management interface.
port-channel p_num Port-Channel Interface.
vlan v_num VLAN interface.
VXLAN vx_num VXLAN interface.

Example

These commands configure the switch to use the IP address assigned to interface loopback 100 as the RP address in SA messages that it originates.

switch(config)# router msdp
switch (config-router-msdp)# originator-id local-interface loopback 100
switch (config-router-msdp)#

peer

The peer command configures the specified address as an MSDP peer, enables MSDP on the switch if it was not previously enabled, and places the switch in Router MSDP Peer Configuration Mode for the specified peer.

The peering session with the device at the specified network is established over a TCP connection. The local-interface command can specify an interface through which the TCP connection is established. When the local-interface command is not used to specify an interface, the connection is established through an interface determined by existing routing algorithms.

The no peer and default peer commands remove the specified MSDP peer configuration by deleting the corresponding peer command from running-config. MSDP is disabled when the last peer command is removed.

Command Mode

Router MSDP Configuration

Command Syntax

peer ip_address

Parameters

ip_address IP address of the MSDP peer to be configured.

Commands Available in Router MSDP Peer Configuration Mode

default-peer
description (MSDP)
disabled (MSDP)
keepalive (MSDP)
local-interface
mesh-group
sa-filter in
sa-filter out
sa-limit

Example

These commands establish an MSDP peer relationship with the peer at 192.168.3.17 and place the switch in the router msdp peer configuration mode for that peer.

switch(config)# router msdp
switch(config-router-msdp)# peer 192.168.3.17
switch(config-router-msdp-peer-192.168.3.17)#

router msdp

The router msdp command places the switch in the router msdp configuration mode, and allows to configure the global IP configuration commands and VRF commands in this mode.

The no router msdp and default router msdp commands removes the corresponding router msdp command from running-config.

Command Mode

Global Configuration

Command Syntax

router msdp

no router msdp

default router msdp

Related Commands

connection retry interval
default-peer
description (MSDP)
disabled (MSDP)
group-limit
ip msdp rejected-limit
keepalive (MSDP)
mesh-group
originator-id local-interface
peer
sa-filter in
sa-filter out
sa-limit

Example

This command places the switch in the router msdp configuration mode.

switch(config)# router msdp
switch(config-router-msdp)#

sa-filter in

The sa-filter in command assigns an IP Access Control List (ACL) as a filter for inbound Source-Active (SA) messages from the configuration-mode MSDP peer connection. The switch only accepts SA messages from the peer that are accepted by the assigned ACL. The switch accepts all SA messages from the peer when an ACL is not assigned as an inbound filter.

Only one ACL can be assigned as an inbound filter to an MSDP peer. Any subsequent sa-filter in commands for the peer replace the existing command.

The no sa-filter in and default sa-filter in commands remove the ACL assignment as an inbound filter by removing the corresponding sa-filter in command from running-config.

Command Mode

Router MSDP Peer Configuration

Router MSDP Peer VRF Configuration

Command Syntax

sa-filter in list list_name

no sa-filter in

default sa-filter in

Parameters

peer_id MSDP peer address (IPv4 address).
list_name name of ACL that filters SA messages.

Related Command

sa-filter out

Guideline

The command accepts standard and extended ACLs. The address field in a standard ACL filters an SA message on its group address.

Example

These commands create an IP ACL named LIST-IN as the inbound SA message filter for the MSDP peer connection to10.4.4.12. The ACL permits SAs from the multicast group 239.14.4.2/28.

switch(config)# ip access-list LIST-IN
switch(config-acl-LIST-IN)# permit ip any 239.14.4.2/28
switch(config-acl-LIST-IN)# exit
switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# sa-filter in list LIST-IN
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Connection status:
   State: Listen
   Connection Source: Loopback100 (10.6.8.6)
SA Filtering:
Input Filter: LIST-IN

sa-filter out

The sa-filter out command assigns an IP Access Control List (ACL) as a filter for outbound Source-Active (SA) messages to the configuration-mode MSDP peer connection, after which the permit statement allows matching SAs to be advertised outbound to the peer. The deny any/deny ip any any at the end of an ACL statement filters any other SAs not matching explicit permit statements. The switch sends all SA messages to the peer when an ACL is not assigned as an output filter to the peer.

Only one ACL can be assigned as an outbound filter to an MSDP peer. Any subsequent sa-filter out commands for the peer replace the existing command.

The no sa-filter out and default sa-filter out commands remove the ACL assignment as an outbound filter by removing the corresponding sa-filter out command from running-config.

Command Mode

Router MSDP Peer Configuration

Router MSDP Peer VRF Configuration

Command Syntax

sa-filter out list list_name

no sa-filter out

default sa-filter out

Parameters

peer_id MSDP peer address (IPv4 address).
list_name name of ACL that filters SA messages.

Related Command

sa-filter in assigns an IP ACL to filter inbound SA messages from the MSDP peer being configured.

Guidelines

The command accepts standard and extended ACLs. The address field in a standard ACLs filters an SA message on its multicast stream source addresss.

Example

These commands assign the IP ACL named LIST-OUT as the outbound SA message filter for the MSDP peer connection to 10.4.4.12.

switch(config)# router msdp
switch(config-router-msdp)# ip access-list LIST-OUT
switch(config-acl-LIST-OUT)# permit ip any  239.14.4.2/28
switch(config-acl-LIST-OUT)# exit
switch(config)# router msdp
switch(config-router-msdp)# peer 10.4.4.12
switch(config-router-msdp-peer-10.4.4.12)# sa-filter out list LIST-OUT
switch(config-router-msdp-peer-10.4.4.12)# show ip msdp peer
MSDP Peer 10.4.4.12
Connection status:
   State: Listen
   Connection Source: Loopback100 ( 10.6.8.6 )
SA Filtering:
Output Filter: LIST-OUT
switch(config-router-msdp-peer-10.4.4.12)#

sa-limit

The sa-limit command specifies the maximum number of Source-Active messages from a specified MSDP peer that the switch allows in the SA cache. SA messages have an expiration period of 90 seconds, during which time they remain in the SA cache. The switch does not accept SA messages from a peer after the peer’s SA limit is reached. By default, The limit to the number of SA messages that the switch can store from a specified peer is 40000, by default.

The no sa-limit and default sa-limit commands restore the SA limit of 40000 for the specified MSDP peer by removing the corresponding sa-limit statement from running-config.

Command Mode

Router MSDP Peer Configuration

Router MSDP Peer VRF Configuration

Command Syntax

sa-limit quantity

no sa-limit

default sa-limit

Parameters

peer_id MSDP peer (IPv4 address).
quantity maximum number of SA messages that the switch can store. Value ranges from 0 to 40000.

Example

This command sets the SA limit of 500 for the MSDP peer at 10.1.1.5.

switch(config)# router msdp
switch(config-router-msdp)# peer 10.1.1.5
switch(config-router-msdp-peer-10.1.1.5)# sa-limit 500
switch(config-router-msdp-peer-10.1.1.5)#

show ip msdp peer

The show ip msdp peer command displays information about specified MSDP peers. The command includes an optional parameter for displaying SAs accepted from the peer.

Command Mode

EXEC Command Syntax

show ip msdp peer [PEER_ADDR][SA_ACCEPT]

Parameters

PEER_ADDR Peers for which command displays information.
- no parameter All peers configured on the switch.
- ipv4_addr Address of specified MSDP peer.
SA_ACCEPT Command displays SAs accepted from the specified peers.
- no parameter Accepted SAs are not displayed.
- accepted-sas Accepted SAs are displayed.

Example

This command displays MSDP information concerning the peer located at 10.2.42.4, including SAs that the switch accepted from this peer.

switch(config)# show ip msdp peer 10.2.42.4 accepted-sas
MSDP Peer 10.2.42.4
Connection status:
  State: Up
  Connection Source: Loopback4 ( 10.2.43.4 )
SA Filtering:
Input Filter: allow-multicast-for-msdp
Output Filter: allow-multicast-for-msdp
SAs accepted:
(10.62.79.30, 234.1.4.2), RP 10.2.42.4
(10.61.79.29, 234.1.4.1), RP 10.2.42.4
(10.62.79.30, 234.1.4.1), RP 10.2.42.4

show ip msdp pim sa-cache

The show ip msdp pim sa-cache command displays the SA cache for the local PIM domain configured on the switch. An SA cache is a table of Source-Active messages that are generated or accepted by the PIM domain.

Command Mode

EXEC

Command Syntax

show ip msdp pim sa-cache

Example

This command displays the SA cache for the local PIM domain.

switch(config)# show ip msdp pim sa-cache
MSDP Source Active Messages for local Pim RP
(10.51.71.23, 234.1.4.1), RP 10.2.43.4
(10.20.91.26, 234.1.4.1), RP 10.2.43.4
(10.51.71.23, 234.1.4.2), RP 10.2.43.4
(10.20.91.21, 234.1.4.1), RP 10.2.43.4
(10.51.79.23, 234.1.4.1), RP 10.2.43.4
(10.20.91.24, 234.1.4.2), RP 10.2.43.4
(10.51.79.23, 234.1.4.2), RP 10.2.43.4
(10.20.91.21, 234.1.4.2), RP 10.2.43.4
(10.20.91.26, 234.1.4.2), RP 10.2.43.4
(10.20.91.24, 234.1.4.1), RP 10.2.43.4

show ip msdp sa-cache

The show ip msdp sa-cache command displays contents of the Source-Active (SA) message cache. The command provides these filter options for displaying partial cache contents:

multicast group address: multicast group
source address and group address

The command can also display unexpired SAs that were rejected by ACL filters or cache limit exceeded conditions.

Command Mode

EXEC

Command Syntax

show ip msdp sa-cache [ADDRESS_FILTER][CONTENTS]

Parameters

ADDRESS_FILTER IPv4 address used to filter SA messages.
- no parameter All SA messages.
- grp_addr Multicast group address (IPv4 address).
- src_addr grp_addr Source and multicast group addresses (two IPv4 addresses).
grp_addr must be a valid multicast address.
- no parameter Displays contents of SA Cache.
- rejected Displays rejected SAs in addition to the SA cache contents.
CONTENTS type of SAs that the command displays.

Example

This command displays the contents of the SA message cache.

switch(config)# show ip msdp sa-cache
MSDP Source Active Cache
(10.61.71.29, 234.1.4.2), RP 10.5.29.4, heard from 10.5.29.4
(10.51.71.23, 234.1.4.1), RP 10.5.29.4, heard from 10.5.29.4
(10.61.79.29, 234.1.4.2), RP 10.5.29.4, heard from 10.5.29.4
(10.53.71.27, 234.1.4.2), RP 10.3.25.4, heard from 10.3.25.4
(10.10.101.24, 234.1.4.1), RP 10.2.44.4, heard from 10.2.44.4
(10.10.151.22, 234.1.4.2), RP 10.1.12.4, heard from 10.1.12.4
(10.61.71.29, 234.1.4.1), RP 10.5.29.4, heard from 10.5.29.4
(10.20.91.21, 234.1.4.1), RP 10.2.44.4, heard from 10.2.44.4
(10.61.79.29, 234.1.4.1), RP 10.2.42.4, heard from 10.2.42.4
(10.53.79.27, 234.1.4.2), RP 10.3.25.4, heard from 10.3.25.4
(10.10.151.28, 234.1.4.2), RP 10.3.25.4, heard from 10.3.25.4
(10.52.79.25, 234.1.4.2), RP 10.2.44.4, heard from 10.2.44.4
(10.52.71.25, 234.1.4.2), RP 10.2.44.4, heard from 10.2.44.4
(10.20.91.24, 234.1.4.1), RP 10.5.29.4, heard from 10.5.29.4
(10.10.151.22, 234.1.4.1), RP 10.1.12.4, heard from 10.1.12.4

show ip msdp sanity

The show ip msdp sanity command performs a consistency check between the multicast routing table and the MSDP Source-Address (SA) caches. When the command detects inconsistencies, it displays the cache entries that are not in the table.

Command Mode

EXEC

Command Syntax

show ip msdp sanity

Examples

This command displays a sanity check that detects no inconsistencies between the SA cache and the multicast routing table.

switch(config)# show ip msdp sanity
PIM SA cache entries not in the MRT
Msdp-learnt MRT entries not in the SA cache
SA cache entries not in the MRT
May-Notify-MSDP entries not in the PIM SA cache
(need not be an error condition)

This command displays inconsistencies between the SA cache and the multicast routing table.

switch(config)# show ip msdp sanity
PIM SA cache entries not in the MRT
Msdp-learnt MRT entries not in the SA cache
SA cache entries not in the MRT
(192.168.3.8, 224.1.154.1)
(192.168.3.35, 224.1.167.1)
(192.168.3.16, 224.1.226.1)
(192.168.3.19, 224.1.246.1)
(192.168.3.17, 224.1.204.1)
(192.168.3.12, 224.1.182.1)
(192.168.3.33, 224.1.150.1)
(192.168.3.26, 224.1.198.1)
(192.168.3.33, 224.1.195.1)
(192.168.3.4, 224.1.246.1)
(192.168.3.37, 224.1.188.1)
(192.168.3.12, 224.1.245.1)
(192.168.3.31, 224.1.206.1)
(192.168.3.35, 224.1.178.1)
(192.168.3.6, 224.1.155.1)
May-Notify-MSDP entries not in the PIM SA cache
(need not be an error condition)
4.1), RP 10.2.42.4

show ip msdp summary

The show ip msdp summary command displays a list of peer addresses, the operational status of the peer, and the number of Source-Active messages in the SA cache from that peer.

Command Mode

EXEC

Command Syntax

show ip msdp summary

Example

This command displays the configured peers, the status of the peers, and the number of SA message received from those peers.

switch(config)# show ip msdp summary
MSDP Peer Status Summary
Peer Address      State   SA Count 
192.168.3.18      Up      0        
192.168.3.16      Up      0        
192.168.3.37      Listen  0        
192.168.3.46      Up      0        
192.168.3.47      Up      0

show msdp mesh-group

The show msdp mesh-group command displays the mesh group membership of MSDP peers that are configured on the switch. An MSDP mesh group is a network of MSDP speakers where each speaker is directly connected to every other speaker. The switch does not forward Source-Active (SA) messages that it receives from a mesh group peer to other peers of the same group.

Command Mode

EXEC

Command Syntax

show msdp mesh-group

Related Command

mesh-group configures the MSDP peer connection as an MSDP mesh group member.

Example

This command displays the mesh group membership of configured MSDP peers.

switch(config)# show msdp mesh-group
Mesh Group: tier_01
        10.24.18.13
Mesh Group: tier_02
        10.26.101.18

show msdp rpf-peer

The show msdp rpf-peer command displays MSDP information for the peer from which the switch accepts SA messages for a specified Rendezvous Point (RP).

The switch examines the BGP routing table to determine the next hop peer toward the originating RP of an SA message. This next hop peer is the Reverse Path Forwarding (RPF) peer. Because the switch receives SA messages from the RPF peer, it forwards the message to all other MSDP peers. The switch rejects identical SA messages that it receives from a non-RPF peer.

Command Mode

EXEC

Command Syntax

show msdp rpf-peer rp_addr

Parameter

rp_addr PIM RP IPv4 address.

Example

This command displays MSDP information for the peer from which the switch accepts SA messages for the RP at 10.5.29.4.

switch(config)# show msdp rpf-peer 10.5.29.4
Rpf Peer is 10.5.29.4 for RP 10.5.29.4

EOS 4.33.0F User Manual

Multicast Source Discovery Protocol (MSDP)

MSDP Introduction

MSDP Description

MSDP Speakers

Network Configuration

Source Active Messages

Reverse Path Forwarding

Default MSDP Peers

MSDP Exchange Processes

Control Information Exchange

MSDP Data Exchange

MSDP Configuration

MSDP Speaker Configuration

Establishing MSDP Peers

Configuring an MSDP Peer

Mesh Groups

Filtering SA Messages

Keep-alive, Hold Time, and Reset Time Configuration

Displaying Peer Information

MSDP Network Configuration

Displaying RPF Peers

Configuring the Default Peer

Managing the SA Cache

Limiting SA Cache Contents

Displaying SA Cache Contents

Verifying Consistency Between the SA Cache and the Routing Table

Configuring MSDP in a non-default VRF

MSDP Commands

MSDP Configuration Commands (Global)

MSDP Peer Configuration Commands

MSDP SA Cache Commands

MSDP Display Commands

clear ip msdp sa-cache

connection retry interval

default-peer

description (MSDP)

disabled (MSDP)

forward register-packets (MSDP)

group-limit

ip msdp rejected-limit

keepalive (MSDP)

local-interface

mesh-group

originator-id local-interface

peer

router msdp

sa-filter in

sa-filter out

sa-limit

show ip msdp peer

show ip msdp pim sa-cache

show ip msdp sa-cache

show ip msdp sanity

show ip msdp summary

show msdp mesh-group

show msdp rpf-peer