SR-TE configuration prerequisites

About this task

To configure SR-TE, the user must first configure prerequisite parameters.

Procedure

  1. Configure the label space partition for the Segment Routing Global Block (SRGB) for all participating routers in the segment routing domain by using the mpls-labels>sr-labels command.
    Example
    mpls-labels
            — sr-labels start 200000 end 200400
        — exit
    
  2. Enable segment routing, traffic engineering, and advertisement of router capability in all participating IGP instances in all participating routers by using the traffic-engineering, advertise-router-capability, and segment-routing commands.
    Example
    ospf 0
            — traffic-engineering
            — advertise-router-capability area
            — loopfree-alternates remote-lfa
            — area 0.0.0.202
                — stub
                    — no summaries
                — exit
                — interface "system"
                    — node-sid index 194
                    — no shutdown
                — exit
                — interface "toSim199"
                    — interface-type point-to-point
                    — no shutdown
                — exit
                — interface "toSim213"
                    — interface-type point-to-point
                    — no shutdown
                — exit
                — interface "toSim219"
                    — interface-type point-to-point
                    — metric 2000
                    — no shutdown
                — exit
            — exit
            — segment-routing
                — prefix-sid-range global
                — no shutdown
            — exit
            — no shutdown
        — exit
    
  3. Configure a segment routing tunnel MTU for the IGP instance, if required, by using the tunnel-mtu command.
    Example
    prefix-sid-range global
        — tunnel-mtu 1500
        — no shutdown
    
  4. Assign a node SID to each loopback interface that a router would use as the destination of a segment routing tunnel by using the node-sid command.
    Example
    ospf 0
            — area 0.0.0.202
                — interface "system"
                    — node-sid index 194
                    — no shutdown
                — exit