When configuring an SR SID (either IPv4 or IPv6) for OSPF or IS-IS instances, the single shared SID for loopback or system interfaces can be enabled by the routing protocol independent sr-mpls>prefix-sids command. One or more IGP protocol instances can have a unique sr-mpls>prefix-sids configured and share this interface SID for an interface. This enhancement relaxes the otherwise imposed SID uniqueness for a loopback/system interface across all configured routing instances on a device.
configure
|
+---router
| +---segment-routing
| | +---sr-mpls
| | | +---prefix-sids [<ip-int-name>]
| | | | no prefix-sids [<ip-int-name>]
| | | | +---no ipv4-sid
| | | | | ipv4-sid index <[0..4294967295]>
| | | | | ipv4-sid label <[32..1048575]>
| | | | +---no ipv6-sid
| | | | | ipv6-sid index <[0..4294967295]>
| | | | | ipv6-sid label <[32..1048575]>
| | | | |
| | | | |---node-sid
| | | | | no node-sid
ipv4-sid
This command is used to configure the SID associated with the primary IPv4 address of the loopback or system interface.
ipv6-sid
This command is used to configure the SID associated with the primary IPv6 address of the loopback or system interface.
node-sid
This command sets the N-flag. The N-flag is set when the prefix SID is a node SID as described in RFC 8402. If the N-flag is not set, the address is an SR anycast SID.
Use the show router segment-routing sr-mpls prefix-sids and tools dump router segment-routing tunnel CLI commands to verify the operation of the shared SIDs. For more information, see the 7450 ESS, 7750 SR, 7950 XRS, and VSR Clear, Monitor, Show, and Tools Command Reference Guide.
*A:Dut-A# show router segment-routing sr-mpls prefix-sids
====================================================================================
Rtr Base SR-MPLS Prefix-SIDs
====================================================================================
Interface Name AF SID Label State
------------------------------------------------------------------------------------
System IPv4 123 100123 enabled
System IPv6 234 100234 ifFailed
loopback.0 IPv4 345 100345 ifDown
loopback.0 IPv6 456 100456 ifDown
loopback.4 IPv4 567 100567 failed
loopback.4 IPv6 - - adminDown
loopback.6 IPv4 - - adminDown
loopback.6 IPv6 678 100678 notPref
------------------------------------------------------------------------------------
No. of Prefix-SIDs: 4
====================================================================================
*A:Dut-C# tools dump router segment-routing tunnel
===================================================================================================
Legend: (B) - Backup Next-hop for Fast Re-Route
(D) - Duplicate
label stack is ordered from top-most to bottom-most
===================================================================================================
--------------------------------------------------------------------------------------------------+
Prefix |
Sid-Type Fwd-Type In-Label Prot-Inst(algoId) |
Next Hop(s) Out-Label(s) Interface/Tunnel-ID |
--------------------------------------------------------------------------------------------------+
1.1.1.3
Node Terminating 20003 IGP-Shared
1.1.1.5
Node Orig/Transit 20005 ISIS-0
10.10.10.2 20005 To_1/1/1(E)
10.10.10.2
Adjacency Transit 524287 ISIS-0
10.10.10.2 3 To_1/1/1(E)
--------------------------------------------------------------------------------------------------+
No. of Entries: 3
--------------------------------------------------------------------------------------------------+
*A:Dut-C#