RSVP-TE LSR

RSVP-TE applies the Resource Reservation Protocol (RSVP) for Traffic Engineering (TE), that is, to distribute MPLS labels for steering traffic and reserving bandwidth.

The eos implementation supports:
  • RSVP-TE core protocol (RFC 2205, RFC 3209), transit role
  • Hello messages (RFC 3209)
  • Refresh overhead reduction (RFC 2961)
  • Cryptographic authentication (RFC 2747)
  • Fast Reroute: facility backup, link-protection/NHOP (RFC 4090)
  • LSP Ping/Traceroute (RFC 4379)
  • Fast Reroute node-protection (Starting in eos Release 4.22.1F)
  • Bandwidth management (Starting in eos Release 4.22.1F)
  • SRLG for Fast Reroute (Starting in eos Release 4.23.1F)
  • MTU signaling (Starting in eos Release 4.23.1F)
  • Soft preemption (Starting in eos Release 4.23.1F)
  • Support for OSPFv2 as the IGP (Starting in eos Release 4.24.2F)
  • Support for LDP entropy label (Starting in eos Release 4.26.0F,RFC 6790)

RSVP-TE LSR Configuration

There is a dedicated configuration sub-mode for RSVP:
(config)# mpls rsvp
(config-mpls-rsvp)#

Enabling RSVP-TE

Enable RSVP-TE globally by issuing no shutdown in the configuration sub-mode. This is the only mandatory setting for RSVP-TE to work. This also globally enables MPLS.
(config-mpls-rsvp)# no shutdown
To disable RSVP-TE, use the shutdown command, which is the default.
(config-mpls-rsvp)# shutdown

There is no per-interface knob to enable and disable RSVP. However, you can only enable RSVP on interfaces thatMPLS is also enabled.

State Refresh Parameter

You can configure the state refresh interval. It describes parameter R in seconds, leading to a state refresh (Path and Resv messages) every 0.5*R to 1.5*R seconds (randomly chosen). The default value is 30 seconds.
(config-mpls-rsvp)# refresh interval 30

Hello Messages

To configure the Hello message interval (seconds) and timeout multiplier (integer), refer to the following example.

In this example, hello messages are sent to all known neighbors every 10 seconds. If no hello responses are received from a neighbor for 4*10=40 seconds, communication is considered to be lost and the neighbor is reset.
(config-mpls-rsvp)# hello interval 10 multiplier 4
The default of 10 seconds with multiplier 4 can be reset with:
(config-mpls-rsvp)# default hello interval
To explicitly disable Hello messages, use the following command:
(config-mpls-rsvp)# no hello interval

Refresh Overhead Reduction

Setting the refresh method to bundled enables the Refresh Overhead Reduction (RFC 2961) that supports the sending of message IDs and refreshing state with refresh messages.
(config-mpls-rsvp)# refresh method bundled
This is also the default setting. To turn off refresh overhead reduction, use explicit.
(config-mpls-rsvp)# refresh method explicit

Cryptographic Authentication Extension

Cryptographic Authentication (RFC 2747) is enabled by setting the authentication type to md5 and configuring an active password.
(config-mpls-rsvp)# authentication type md5

The default is none, which disables cryptographic authentication.

Authentication secrets are configured with an index. One of the indices should be chosen as the actively used password:
(config-mpls-rsvp)# authentication index 1 password s3cr3t
(config-mpls-rsvp)# authentication index 1 active

The active password is used to authenticate outgoing messages. All configured passwords are accepted for authentication of incoming packets, which allows smooth key rollover.

Password obfuscation is available:
(config-mpls-rsvp)# authentication index 1 password 7 07092E43
The size of the sequence number reorder window can be changed to accommodate a larger number of out-of-order packets. A value of N means that a packet is accepted if all earlier received packets with a higher sequence number are within the preceding N-1 packets.
(config-mpls-rsvp)# authentication sequence-number window 5

The default value is 5. A value of 1 effectively turns off support for packet reordering.

Fast Reroute Extension

Support for Fast ReRoute (FRR) link protection/NHOP (RFC 4090) is enabled by setting the Fast Reroute mode to link-protection.
(config-mpls-rsvp)# fast-reroute mode link-protection
To turn off FRR, change the mode to the default setting none.
(config-mpls-rsvp)# fast-reroute mode none

This setting only applies to Point of Local Repair (PLR) behavior, for example, the router is the upstream node relative to a to-be-protected link over which an LSP is routed. Merge Point (MP) behavior is always enabled and not affected by this setting.

Support for Node Protection is present starting in eos Release 4.22.1F, so the above CLI also accepts an additional mode node-protection.

You can change the revertive behavior of the FRR from the global revertive mode to the local revertive mode. In the global revertive mode, an LSR that is re-routed over a bypass tunnel because its downstream link is dead keeps using the bypass tunnel even after the link has recovered. This expects the headend router to set up a new LSP upon notification that a link is not available anymore. In the local revertive mode, the LSR switches back to using the primary link after recovery.
(config-mpls-rsvp)# fast-reroute reversion local
The default for reversion is global.
(config-mpls-rsvp)# fast-reroute reversion global

Shared Risk Link Group

Starting in eos Release 4.23.1F, there is an additional config command to configure SRLG mode.

srlg [strict]

no srlg [strict]

default srlg [strict]

This command specifies if link SRLGs of a primary LSP are to be considered as constraints while creating a fast-reroute bypass tunnel with either link or node protection. When srlg is specified with thestrict keyword, then if a path for a bypass tunnel excluding SRLGs of the next-hop interface of primary LSP can not be found, RSVP does not setup the bypass tunnel. When srlg is specified without a strict keyword, then a bypass tunnel is setup with as many links as possible that exclude the SRLGs of the next-hop interface of primary LSP and where such links are not available, links that have the least number of SRLGs which are to be excluded are used.

When this CLI is not configured, the behavior remains the same as before, which is to turn off SRLG processing. Therefore, the no and default versions of the command take you back to the default of SRLG processing being turned off.

The SRLGs of an interface can be configured using the following traffic-engineering CLI as below:
(config)# interface Et1
(config-if-Et1)# traffic-engineering srlg 100

(config)# interface Et2
(config-if-Et2)# traffic-engineering srlg 200
Note: Although a large number of SRLGs can be configured on an interface (ranging from 0 to 2^32 -1), CSPF only takes into account a maximum of 16 SRLGs for finding a path with SRLG constraints.

CSPF Configuration Command

RSVP-TE uses CSPF to compute the FRR backup path. CSPF can be throttled to avoid frequent path changes when there are frequent network events. The following CLI command is used under the router traffic-engineering mode to specify how frequently CSPF is to run after a network event by specifying the initial wait interval, back-off interval, and maximum wait interval for CSPF.

cspf delay [initial n back-off n] max n

All three values are in milliseconds and default to 100, 200, and 1000 milliseconds, respectively.

Traffic-engineering Configuration Commands

For CSPF to compute the FRR backup path to a particular destination, enable traffic-engineering on all the IGP enabled interfaces, and enable globally the traffic engineering extensions. For IS-IS, enable under router isis mode, and for OSPFv2, enable under router ospf. This is required for the IGP to start exchanging TE-related attributes with peers and build its topology database.

Also, CSPF needs some notion of router ID to uniquely identify a router, so that it can find a path to it. CSPF also uses self router-id as a source for running SPF. So a router-id is required to be configured under router traffic-engineering mode for CSPF to function properly.

MTU Signaling

Starting in eos Release 4.23.1F, MTU along a path can be signaled using RSVP.

Example

mtu signaling

no mtu signaling

default mtu signaling

RSVP can discover the lowest MTU used along an LSP by evaluating and updating, at each hop, the composed MTU, stored in the General Parameters fragment of an AdSpec object in RSVP Path messages.

At each RSVP hop, when MTU signaling is enabled, the value is updated by taking the minimum between the downstream interface for an LSP and the composed MTU value from the incoming Path message.

When the feature is disabled, the composed MTU is not updated.

Soft Preemption

Starting in eos Release 4.23.1F, soft preemption is supported, which enables deferred failure of RSVP-TE LSPs on link oversubscription. A preemption timer value can be used to configure a delay on a transit router to support LSPs signaled with soft preemption enabled by the headend (RFC 5712).

preemption method [hard | soft ] timer t

no preemption method [hard | soft ] timer t

default preemption method [hard | soft ] timer t

The default preemption method is soft preemption with a timer value of 30 seconds.

In this example, the preemption method is soft preemption with a timer value of 10 seconds.

(config-mpls-rsvp)# preemption method soft timer 10
Setting the preemption method to hard preemption results in a timer value of 0 seconds and disables the feature.
(config-mpls-rsvp)# preemption method hard
Sample Configuration
switch(config)# ip routing
!
switch(config)# mpls ip
!
switch(config)# interface Ethernet1
switch(config-if-Et1)# no switchport
switch(config-if-Et1)# ip address 10.0.0.1/24
switch(config-if-Et1)# isis enable isis
switch(config-if-Et1)# traffic-engineering
switch(config-if-Et1)# traffic-engineering bandwidth 100 percent
switch(config-if-Et1)# traffic-engineering metric 5
!
switch(config)# router traffic-engineering
switch(config-te)# router-id ipv4 0.1.1.1
!
switch(config)# router isis isis
switch(config-router-isis)# net 49.0000.0000.0000.1111.00
switch(config-router-isis)# is-type level-2
   !
switch(config-router-isis)# address-family ipv4 unicast
switch(config-router-isis-af)# maximum-paths 32
   !
switch(config-router-isis-af-te)# traffic-engineering
switch(config-router-isis-af-te)# no shutdown
switch(config-router-isis-af-te)# is-type level-2
!
switch(config)# mpls rsvp
switch(config-mpls-rsvp)# no shutdown
!
The following displays the overall state of RSVP.
switch> show mpls rsvp
Administrative state: enabled
Operational state: up
Refresh interval: 30 seconds
Refresh reduction: enabled
Hello messages: enabled
   Hello interval: 10 seconds
   Hello multiplier: 4
Fast Re-Route: disabled
   Mode: none
   Hierarchical FECs: enabled
Cryptographic authentication: disabled
MTU signaling: disabled
Number of sessions: 1
   Ingress/Transit/Egress: 0/1/0
Number of LSPs: 1
   Operational: 1
   Ingress/Transit/Egress: 0/1/0
   Currently using bypass tunnels: 0
Number of bypass tunnels: 0
Number of neighbors: 2
Number of interfaces: 2
The following displays the RSVP neighbors.
switch> show mpls rsvp neighbor
Neighbor 10.0.1.1
   Upstream for
      Session #1 LSP #1
   Downstream for
   Neighbor uptime: 00:01:24
   Authentication type: disabled
   Last hello received: 1 seconds ago
   Last hello sent: 1 seconds ago
   Bypass tunnel: not requested
Neighbor 10.0.2.2
   Upstream for
   Downstream for
  	Session #1 LSP #1
   Neighbor uptime: 00:01:24
   Authentication type: disabled
   Last hello received: -
   Last hello sent: 31 seconds ago
   Bypass tunnel: not requested
The following displays a summary of RSVP neighbors by IP address.
switch> show mpls rsvp neighbor summary
Neighbor                             	Role   	Sessions LSPs
======================================== ========== ======== ========
10.0.1.1                             	Upstream   1    	1
10.0.2.2                             	Downstream 1    	1
The following displays RSVP sessions.
switch> show mpls rsvp session
Session #1
   Destination address: 0.4.4.4
   Tunnel ID: 0
   Extended Tunnel ID: 0.1.1.1
   Role: transit
  	LSP #1
        State: up
        Type: primary
        Source address: 0.1.1.1
        LSP ID: 1
        LSP uptime: 00:02:38
        Session name: Session1
        Local label: 100000
        Downstream label: 100000
        Upstream neighbor: 10.0.1.1
           Last refresh received: 17 seconds ago
           Last refresh sent: 10 seconds ago
        Downstream neighbor: 10.0.2.2
           Last refresh received: 7 seconds ago
           Last refresh sent: 9 seconds ago
        Bypass tunnel: not requested
The following displays a summary of RSVP sessions.
switch> show mpls rsvp session summary
Session  Destination   LSP      Name        Role    Bypass State
======== ============= ======== =========== ======= ====== ======
1        0.4.4.4       1        Session1    transit n/req  up
The following displays details of RSVP sessions.
switch> show mpls rsvp session detail
Session #1
   Destination address: 0.4.4.4
   Tunnel ID: 0
   Extended Tunnel ID: 0.1.1.1
   Role: transit
  	LSP #1
        State: up
        [...]
        MTU Signaling: enabled
           Received Path MTU: 1800 bytes
           Sent Path MTU: 1500 bytes
  [...]
The following displays RSVP message counters per interface.
switch> show mpls rsvp counters
Received Messages:

Interface  Path  PathTear  PathErr  Resv  ResvTear  ResvErr  Srefresh  Other  Errors  
---------  ----  --------  -------  ----  --------  -------  --------  -----  ------  
Ethernet1  5     0         0        0     0         0        8         51     1  	 
Ethernet2  0     0         0        14    0         0        0         0      0  	 

Sent Messages:

Interface  Path  PathTear  PathErr  Resv  ResvTear  ResvErr  Srefresh  Other  Errors  
---------  ----  --------  -------  ----  --------  -------  --------  -----  ------  
Ethernet1  0     0         0        4     0         0        9         49     0  	 
Ethernet2  13    0         0        0     0         0        0         4      0

Path Specifications

Path specifications can be explicit and dynamic depending on Constrained Shortest Path First (CSPF) search procedure to find a path in the network topology.

Explicit Path Specifications

The operator provides all hops in the path explicitly. The given path is used directly as the Explicit Route Object (ERO) in RSVP Path messages. All hops are implicitly strict hops. Explicit loose hops are not supported. The submode to configure explicit paths is entered by specifying the name.
switch(config-te-rsvp)# path MyPath explicit
switch(config-te-rsvp-path-expl-MyPath)#
Each hop is specified explicitly in order.
switch(config-te-rsvp-path-expl-MyPath)# hop 10.0.12.2
(config-te-rsvp-path-expl-MyPath)# hop 10.0.34.4
Adding hops with before and after create a unique internal ordering in show running-config.
switch(config-te-rsvp-path-expl-MyPath)# hop 10.0.23.3 before 10.0.34.4
switch(config-te-rsvp-path-expl-MyPath)# hop 10.0.45.5 after 10.0.34.4
no hop command removes the hop.
switch(config-te-rsvp-path-expl-MyPath)# no hop 10.0.12.2
show active command retrieves the currently active configuration. The pending configuration that becomes active upon exiting the submode is retrieved with show pending command; the difference between these two can be retrieved with show diff command. 
switch(config-te-rsvp-path-expl-MyPath)# show active
router traffic-engineering
   rsvp
      path MyPath explicit
         hop 10.0.23.3
         hop 10.0.34.4
         hop 10.0.45.5
(config-te-rsvp-path-expl-MyPath)# show pending
   hop 10.0.23.3
   hop 10.0.44.4
   hop 10.0.45.5
(config-te-rsvp-path-expl-MyPath)# show diff
 hop 10.0.23.3
-hop 10.0.34.4
+hop 10.0.44.4
 hop 10.0.45.5
(config-te-rsvp-path-expl-MyPath)#
exit command keeps the changes in the submode.
switch(config-te-rsvp-path-expl-MyPath)# exit
switch(config-te-rsvp)#
abort command discards the changes in the submode.
switch(config-te-rsvp-path-expl-MyPath)# abort
switch(config-te-rsvp)#

Dynamic Path Specifications

In a dynamic path specification, the operator provides constraints with which a CSPF procedure finds a path in the network topology. The CSPF result is a list of strict hops which forms the ERO.

The submode to configure dynamic paths is entered by specifying the name with dynamic.

switch(config-te-rsvp)# path MyPath dynamic
switch(config-te-rsvp-path-dyn-MyPath)#
Exclude hop constraints specify that CSPF must not choose the specified address on the path. Note that other interfaces on the same node may be used.
switch(config-te-rsvp-path-dyn-MyPath)# hop 10.0.56.6 exclude
Include hop constraints specify these hops included in the computed path in a certain order. A hop can be loose which allows other hops to be filled by the CSPF procedure. The keywords before and after work in the submode for explicit paths.
switch(config-te-rsvp-path-dyn-MyPath)# hop 10.0.23.3
switch(config-te-rsvp-path-dyn-MyPath)# hop 10.0.45.5 loose
switch(config-te-rsvp-path-dyn-MyPath)# hop 10.0.12.2 before 10.0.23.3
switch(config-te-rsvp-path-dyn-MyPath)# hop 10.0.67.7 loose after 10.0.45.5

Tunnel Specifications

Tunnel specification has its own sub-mode.

switch(config-te-rsvp)# tunnel MyTunnel
switch(config-te-rsvp-tunnel-MyTunnel)#

Each tunnel has a tunnel destination IP.

switch(config-te-rsvp-tunnel-MyTunnel)# destination ip 10.2.2.2
A tunnel specifies for path for its LSP(s). It configures the primary LSP.
switch(config-te-rsvp-tunnel-MyTunnel)# path MyPath
A secondary LSP is configured, when the primary LSP is not available. Only one secondary path can be configured per tunnel.
switch(config-te-rsvp-tunnel-MyTunnel)#path MyOtherPath secondary pre-signaled
A tunnel reserves bandwidth along the path. The bandwidth can be configured explicitly.
switch(config-te-rsvp-tunnel-myTunnel)# bandwidth 10 mbps
Auto bandwidth specifies the minimum and maximum bandwidth used for the tunnel and adjusts bandwidth with an adjustment period based on the observed traffic going over the tunnel. The adjustment period is specified in seconds.
switch(config-te-rsvp-tunnel-myTunnel)# bandwidth auto min 1 mbps max 5 mbps adjustment-period 60
Setup and hold priorities from 0 to 7 can be configured for the tunnel, where 0 is most preferred and 7 the least preferred.
switch(config-te-rsvp-tunnel-myTunnel)# priority setup 5 hold 3
By default, a tunnel is not enabled.
switch(config-te-rsvp-tunnel-myTunnel)# no shutdown
Changes in the sub-mode only take effect when the sub-mode is exited normally for show active, show pending and show diff commands.
switch(config-te-rsvp-tunnel-myTunnel)# exit
switch(config-te-rsvp)#
Changes are discarded when sub-mode is aborted.
switch(config-te-rsvp-tunnel-myTunnel)# abort
switch(config-te-rsvp)#
Periodic tunnel optimization is configured globally as well as individually for a specific tunnel. For global periodic tunnel optimization, the optimization interval is configured in config-te-rsvp mode, and this configuration automatically gets applied to all the RSVP tunnels.
switch(config-te-rsvp)# optimization interval 3600 seconds
switch(config-te-rsvp)#
The optimization interval can also be individually configured on a tunnel by entering the command in tunnel sub-mode. The optimization interval configured in the tunnel sub-mode overrides the optimization interval configured globally.
switch(config-te-rsvp)# tunnel myTunnel
switch(config-te-rsvp-tunnel-myTunnel)# optimization interval 3600 seconds
Optimization can also be disabled on a specific tunnel. Optimization is enabled for all the tunnels with a common interval but a specific tunnel has optimization disabled.
switch(config-te-rsvp)# optimization interval 3600 seconds
switch(config-te-rsvp)# tunnel myTunnel
switch(config-te-rsvp-tunnel-myTunnel)# optimization disabled
alias IPv4 and IPv6 endpoints per tunnel allow these additional next hops to resolve using the existing tunnel. The command allows a maximum of 15 alias endpoints to be configured per tunnel.
switch(config-te-rsvp-tunnel-myTunnel)# alias endpoint 5.5.5.5
switch(config-te-rsvp-tunnel-myTunnel)# alias endpoint 2001::10
The split-tunnel command allows splitting the bandwidth for a tunnel between multiple sessions. With this enabled, RSVP automatically creates multiple LSPs with smaller bandwidth reservations for a single tunnel.
switch(config-te-rsvp-tunnel-myTunnel)# split-tunnel quantum 10 kbps
switch(config-te-rsvp-tunnel-myTunnel)# split-tunnel quantum 10 kbps sub-tunnels limit 20

IGP Shortcut in IS-IS

IGP shortcuts enable traffic to get forwarded along paths computed to take advantage of traffic-engineered paths setup using RSVP using a modified SPF algorithm. This enables operators to take advantage of TE capabilities of RSVP tunnels which traverse over links satisfying bandwidth, latency or fast reroute considerations.

IGP shortcuts are enabled on a RSVP Label Edge Router (LER) selectively on specific RSVP tunnels. When IGP shortcut is enabled, IP routes resolving over RSVP tunnels are installed in FIB. As a result all IP traffic including control plane traffic is forwarded through IGP shortcut tunnels. All protocols relying on FIB for nexthop resolution such as Static routes or BGP is also resolved over IGP shortcuts.

Configuring IGP Shortcut on RSVP Tunnel

On a RSVP LER, IGP shortcut is enabled individually on each RSVP tunnel that is intended for them. No configuration changes are needed on any of the RSVP Label Switch Routers. 

switch(config)# router traffic-engineering
switch(config-te)# rsvp
switch(config-te-rsvp)# tunnel R3b
switch(config-te-rsvp-tunnel-T1)# igp shortcut
switch(config-te-rsvp-tunnel-T1)# exit

IGP shortcuts is enabled by default in IS-IS, following command disables this under the IS-ISaddress-family ipv4 mode.

switch# conf terminal
switch(config)# router isis inst1
switch(config-router-isis)# address-family ipv4
switch(config-router-isis-af)# igp shortcut disabled

Limitations

  • IGP shortcut is only supported for IPv4.
  • IGP shortcuts can only be computed over RSVP tunnels'
  • IS-IS must be enabled on the loopback interface whose primary IP address is used as the RSVP tunnel end point.
  • This is only available in the multi-agent routing protocol model.
  • TI-LFA protection is not enabled for Segment Routing destinations reachable via IGP shortcuts.

Show Commands

The show traffic-engineering rsvp tunnel command gives the information about the paths for its LSP(s).
switch# show traffic-engineering rsvp tunnel
Tunnel TestTunnel
   Source: 10.1.1.1
   Destination: 10.4.4.4
   State: up
   Bandwidth: 0.0 bps, mode explicit
   LSPs: 2
   Active path: primary
   Primary path: Path1to4
      State: up, in use
      Path (dynamic):
         10.0.12.2
         10.0.23.3
         10.0.34.4
   Secondary path: Path1to4detour
      State: up
      Path (explicit):
         10.0.16.6
         10.0.67.7
         10.0.37.3
         10.0.34.4
The show traffic-engineering rsvp tunnel lsp command gives the details of the paths for its LSP(s).
switch(config)# show traffic-engineering rsvp tunnel lsp
Tunnel TestTunnel
   Source: 10.1.1.1
   Destination: 10.4.4.4
   State: up
   Bandwidth: 0.0 bps, mode explicit
   LSPs: 2
   Active path: primary
   LSP 1:
      Path specification: Path1to4, primary
      CSPF Path ID: 10001
      Bandwidth: 0.0 bps
      State: up, in use
      Path (dynamic):
         10.0.12.2
         10.0.23.3
         10.0.34.4
   LSP 2:
      Path specification: Path1to4detour, secondary
      Bandwidth: 0.0 bps
      State: up
      Path (explicit):
         10.0.16.6
         10.0.67.7
         10.0.37.3
         10.0.34.4
The show traffic-engineering rsvp tunnel detail command gives the details of the tunnel.
switch# show traffic-engineering rsvp tunnel detail
Tunnel TestTunnel
   Source: 10.1.1.1
   Destination: 10.4.4.4
   Additional endpoints:
      5.5.5.5
      2001::10 
   State: up
   Bandwidth: 0.0 bps, mode explicit
      Setup priority: 7
      Hold priority: 0
   MTU signaling: disabled
Periodic optimization: disabled
   Session #4
   Tunnel index: 1
   LSPs: 2
LDP tunneling: enabled
   IGP shortcut: enabled
   Active path: primary
   Primary path: Path1to4
      State: up, in use
      CSPF Path ID: 10001
      Path (dynamic):
         10.0.12.2
         10.0.23.3
         10.0.34.4
   Secondary path: Path1to4detour
      State: up
      Path (explicit):
         10.0.16.6
         10.0.67.7
         10.0.37.3
         10.0.34.4
The show traffic-engineering rsvp tunnel history command gives the history for the paths.
switch# show traffic-engineering rsvp tunnel history
Tunnel TestTunnel
Mon 2020-07-13 07:04:44 CSPF query on primary path
Mon 2020-07-13 07:04:44 State change: down
Mon 2020-07-13 07:04:44 LSP #1 added
Mon 2020-07-13 07:04:44 CSPF reply for primary path, path found
Mon 2020-07-13 07:04:44 LSP #2 added
Mon 2020-07-13 07:04:46 State change: up using primary path
LSP #1
Mon 2020-07-13 07:04:44 LSP created
Mon 2020-07-13 07:04:44 State change: establishing
Mon 2020-07-13 07:04:46 State change: up
LSP #2
Mon 2020-07-13 07:04:44 LSP created
Mon 2020-07-13 07:04:44 State change: establishing
Mon 2020-07-13 07:04:47 State change: up
The show isis summary command shows the status of IGP shortcut configuration if IGP shortcut is enabled for IS-IS.
switch# show isis summary
IS-IS Instance: inst1 VRF: default
  Instance ID: 0
  System ID: 1111.1111.1001, administratively enabled
  Router ID: IPv4: 1.0.5.1
  Multi Topology disabled, not attached
  IPv4 Preference: Level 1: 115, Level 2: 115
  IPv6 Preference: Level 1: 115, Level 2: 115
  IS-Type: Level 2, Number active interfaces: 3
  Routes IPv4 only
  LSP size maximum: Level 1: 1492, Level 2: 1492
  …
  Shortcut SPF for IGP: Enabled
  …
The show isis network topology command verifies the best path details computed after IS-IS SPF. RSVP tunnel details are shown if the destination is reachable through a IGP shortcut.
switch# show isis network topology
IS-IS Instance: inst1 VRF: default
 IS-IS paths to level-2 routers
  System Id        Metric   IA Metric Next-Hop         Interface                SNPA
  1111.1111.1003   10    0         1111.1111.1003   RSVP LER tunnel index 5  IGP Shortcut

Show Commands

RSVP Show Commands

Use the show mpls rsvp command to display the overall state of the RSVP.
switch> show mpls rsvp   	 
Administrative state: enabled
Operational state: up
Refresh interval: 30 seconds
Refresh reduction: enabled
Hello messages: enabled
   Hello interval: 10 seconds
   Hello multiplier: 4
Fast Re-Route: disabled
   Mode: none
   Hierarchical FECs: enabled
Cryptographic authentication: disabled
MTU signaling: disabled
Number of sessions: 1
   Ingress/Transit/Egress: 0/1/0
Number of LSPs: 1
   Operational: 1
   Ingress/Transit/Egress: 0/1/0
   Currently using bypass tunnels: 0
Number of bypass tunnels: 0
Number of neighbors: 2
Number of interfaces: 2
Use the show mpls rsvp neighbor command to display RSVP neighbors.
switch> show mpls rsvp neighbor
Neighbor 10.0.1.1
   Upstream for
      Session #1 LSP #1
   Downstream for
   Neighbor uptime: 00:01:24
   Authentication type: disabled
   Last hello received: 1 seconds ago
   Last hello sent: 1 seconds ago
   Bypass tunnel: not requested
Neighbor 10.0.2.2
   Upstream for
   Downstream for
  	Session #1 LSP #1
   Neighbor uptime: 00:01:24
   Authentication type: disabled
   Last hello received: -
   Last hello sent: 31 seconds ago
   Bypass tunnel: not requested
Use the show mpls rsvp neighbor summary command to display neighbors filtered by IP address. 
switch> show mpls rsvp neighbor summary
Neighbor             Role       Sessions LSPs
==================== ========== ======== ========
10.0.1.1             Upstream   1    	1
10.0.2.2             Downstream 1    	1
or use the show mpls rsvp session command.
switch> show mpls rsvp session
Session #1
   Destination address: 0.4.4.4
   Tunnel ID: 0
   Extended Tunnel ID: 0.1.1.1
   Role: transit
  	LSP #1
        State: up
        Type: primary
        Source address: 0.1.1.1
        LSP ID: 1
        LSP uptime: 00:02:38
        Session name: Session1
        Local label: 100000
        Downstream label: 100000
        Upstream neighbor: 10.0.1.1
           Last refresh received: 17 seconds ago
           Last refresh sent: 10 seconds ago
        Downstream neighbor: 10.0.2.2
           Last refresh received: 7 seconds ago
           Last refresh sent: 9 seconds ago
        Bypass tunnel: not requested
Session #ID and LSP #ID are internal values that are locally significant. Use these to filter sessions in the show mpls rsvp session summary command and in LSP ping and traceroute commands (see below). Sessions can further be filtered by name, destination, router role (transit/ingress/egress), and state.
switch> show mpls rsvp session summary
Session  Destination        LSP      Name         Role    Bypass State
======== ================== ======== ============ ======= ====== =========
1        0.4.4.4             1        Session1    transit n/req  up
Beginning with eos Release 4.23.1F, use the show mpls rsvp session detail command to display detailed information of RSVP sessions.
switch> show mpls rsvp session detail
Session #1
   Destination address: 0.4.4.4
   Tunnel ID: 0
   Extended Tunnel ID: 0.1.1.1
   Role: transit
  	LSP #1
        State: up
        [...]
        MTU Signaling: enabled
           Received Path MTU: 1800 bytes
           Sent Path MTU: 1500 bytes
  [...]
Use the show mpls rsvp counters command to display RSVP message counters by interface.
switch> show mpls rsvp counters
Received Messages:

Interface  Path  PathTear  PathErr  Resv  ResvTear  ResvErr  Srefresh  Other  Errors  
---------  ----  --------  -------  ----  --------  -------  --------  -----  ------  
Ethernet1  5     0         0        0     0         0        8         51     1  	 
Ethernet2  0     0         0        14    0         0        0         0      0  	 

Sent Messages:

Interface  Path  PathTear  PathErr  Resv  ResvTear  ResvErr  Srefresh  Other  Errors  
---------  ----  --------  -------  ----  --------  -------  --------  -----  ------  
Ethernet1  0     0         0        4     0         0        9         49     0  	 
Ethernet2  13    0         0        0     0         0        0         4      0

CSPF Show Commands

RSVP-TE uses CSPF to compute the FRR backup path. Starting from eos Release 4.23.1F, if srlg is configured in RSVPconfig to exclude SRLG, then details about the SRLG related constraint attributes are also shown as in the following show commands.

Use the show traffic-engineering cspf path command to display all the paths computed by CSPF. In the following example, path 20.0.0.1 is selected for display.
switch> show traffic-engineering cspf path 20.0.0.1 20.0.0.1

Destination     Constraint                           Path
20.0.0.1        exclude Ethernet1                    0.1.1.1
                exclude SRLG of Ethernet1            0.1.1.2
                                                     0.2.2.2
                                                     3.3.3.2
                exclude Ethernet2                    0.1.1.1
                                                     0.1.1.2
                                                     0.2.2.2
                                                     3.3.3.2
Using the show traffic-engineering cspf path detail command, path 20.0.0.1 is displayed in detail.
switch> show traffic-engineering cspf path 20.0.0.1 detail

Destination: 20.0.0.1
   Path Constraint: exclude Ethernet1
                    exclude SRLG of Ethernet1: orange-link (500), 
                       green-link (400), 100, red-link (200), 600
   Request Sequence number: 1
   Response Sequence number: 1
   Number of times path updated: 2
   Last updated: 00:01:58
   Reoptimize: Always
   
   Path:
  	0.1.1.1
  	0.1.1.2
  	0.2.2.2
  	3.3.3.2

      Path Constraint: exclude Ethernet2
      Request Sequence number: 2
      Response Sequence number: 2
      Number of times path updated: 3
      Last updated: 00:00:38
      Reoptimize: Always
      Path:
  	0.1.1.1
  	0.1.1.2
  	0.2.2.2
  	3.3.3.2
Displaying the Traffic-engineering Database

You can display the topology used for CSPF computations by using the show traffic-engineering database command. Starting from eos Release 4.23.1F, the SRLG group details of a neighbor are shown if it is advertised.

Beginning with eos Release 4.24.2F, information for the OSPFv2 topology, if configured, displays.
switch# show traffic-engineering database

TE Router-ID: 1.0.0.2
  Source: IS-IS Level-1 IPv4 Topology Database
    IS-IS System-ID: 1111.1111.1001
      Number of Links: 2
        Network type: P2P 
          Neighbor: 1111.1111.1002
		 Administrative group (Color): 0x123a
            TE Metric: 30
            IPv4 Interface Addresses:
              20.20.20.1
              192.168.20.1
            IPv4 Neighbor Addresses:
              20.20.20.2
              192.168.20.2
            Maximum link BW: 25.00 Gbps
            Maximum reservable link BW: 10.00 Mbps
            Unreserved BW:
              TE class 0: 9.00 Mbps     TE class 1: 9.00 Mbps
              TE class 2: 8.5.00 Mbps   TE class 3: 8.00 Mbps
              TE class 4: 7.00 Mbps     TE class 5: 7.50 Mbps
              TE class 6: 6.00 Mbps     TE class 7: 6.00 Mbps                                                                                        
        Network Type: LAN  
          Neighbor: 1111.1111.1003.02
            TE Metric: 30    
        	Administrative Group: 0x12     
            IPv4 Local Addresses:
              30.30.30.1                                                                                                      
            Maximum Link BW: 10.00 Gbps                                                                                       
            Maximum Reservable Link BW: 10.50 Gbps                                                                             
            Unreserved BW:                                                                                                     
              TE-Class 0: 8.50 Gbps       TE-Class 1: 8.70 Gbps                                                               
              TE-Class 2: 7.50 Gbps       TE-Class 3: 7.25 Gbps                                                               
              TE-Class 4: 6.50 Gbps       TE-Class 5: 7.30 Gbps                                                               
              TE-Class 6: 3.50 Gbps       TE-Class 7: 7.20 Gbps
  Source: IS-IS Level-2 IPv4 Topology Database  
    IS-IS System-ID: 1111.1111.1003
      Number of Links: 1  
        Network Type: LAN
         Neighbor: 1111.1111.1003.16
           IPv4 Local Addresses:
             40.40.40.1
            Maximum link BW: 10.00 Gbps
            Maximum reservable link BW: 5.00 Gbps
            Unreserved BW:
              TE class 0: 4.00 Gbps     TE class 1: 4.00 Gbps
              TE class 2: 4.00 Gbps     TE class 3: 4.00 Gbps
              TE class 4: 3.00 Gbps     TE class 5: 3.00 Gbps
              TE class 6: 3.00 Gbps     TE class 7: 3.00 Gbps
  Source: OSPFv2 Instance ID 33 Area-ID 0.0.0.0 Topology Database
    OSPFv2 Router-ID: 1.2.3.4
      Number of Links: 2
        Network type: P2P
          Neighbor: 3.4.5.6
            Administrative group (Color): 0x123a
            TE metric: 30
            IPv4 Interface Addresses:
              20.20.20.1
              192.168.20.1
            IPv4 Neighbor Addresses:
              20.20.20.2
              192.168.20.1
            Maximum link BW: 25.00 Gbps
            Maximum reservable link BW: 10.00 Mbps
            Unreserved BW:
              TE class 0: 9.00 Mbps    TE class 1: 9.00 Mbps
              TE class 2: 8.50 Mbps    TE class 3: 8.00 Mbps
              TE class 4: 7.00 Mbps    TE class 5: 7.50 Mbps
              TE class 6: 6.00 Mbps    TE class 7: 6.00 Mbps
        Network type: LAN
          Neighbor: 2.3.4.5
            Administrative group (Color): 0x12
            TE metric: 30
            IPv4 Interface Addresses:
              30.30.30.1
            IPv4 Neighbor Addresses:
              0.0.0.0
            Maximum link BW: 10.00 Gbps
            Maximum reservable link BW: 10.5 Gbps
            Unreserved BW:
              TE class 0: 8.50 Gbps    TE class 1: 8.70 Gbps
              TE class 2: 7.50 Gbps    TE class 3: 7.25 Gbps
              TE class 4: 6.50 Gbps    TE class 5: 7.30 Gbps
              TE class 6: 3.50 Gbps    TE class 7: 7.20 Gbps                                                                                         
TE Router-ID: 1.0.0.3
  Source: IS-IS Level-1 IPv4 Topology Database
    IS-IS System-ID: 1111.1111.1004
      Number of Links: 2
        Network type: P2P
          Neighbor: 1111.1111.1002
          IPv4 Interface Addresses:
              1.0.5.1
            IPv4 Neighbor Addresses:
              1.0.5.2
            Maximum link BW: 50.00 Gbps
            Maximum reservable link BW: 10.00 Gbps
            Unreserved BW:
              TE class 0: 8.00 Gbps     TE class 1: 8.00 Gbps
              TE class 2: 8.00 Gbps     TE class 3: 8.00 Gbps
              TE class 4: 7.00 Gbps     TE class 5: 7.00 Gbps
              TE class 6: 7.00 Gbps     TE class 7: 7.00 Gbps
            Shared Risk Link Group:
              Group: 100
              Group: green-link (150)

Limitations

RSVP-TE LSR contains the following limitations:
  • Supports only IPv4.
  • Supports only the default VRF.
  • Supports only strict EROs with host hops (/32).
  • Supports only transit role functionality.
  • Traffic Engineering links with secondary IP addresses are not supported.
  • The maximum number of supported RSVP sessions and LSPs is 5000.
  • For FRR, the maximum number of supported LSPs per interface is 2000.
  • Changing the RSVP FRR mode while a bypass tunnel is already in use can bring down both primary and bypass tunnels which cause traffic loss.
  • Changing the RSVP SRLG mode while a bypass tunnel is already in use could bring down both primary and bypass tunnels which cause traffic loss.
  • The maximum number of IS-IS/OSPFv2 routers supported by CSPF on a single broadcast network is 30.
  • The maximum number of IS-IS/OSPFv2 adjacencies supported by CSPF for a single router is 500.
  • CSPF only takes into account a maximum of 16 SRLGs per TE link, when excluding SRLGs while computing a path.