Configuration

Once a topology without a backup path from P2 to PE5 is achieved, apply the commands shown on router P2 to enable microloop avoidance.

The following commands enable microloop avoidance for segment routing in the IS-IS protocol and configure an RIB update delay of 60,000 milliseconds or 60 seconds:

P2

router isis IGP
address-family ipv4 unicast
  microloop avoidance segment-routing
  microloop avoidance rib-update-delay 60000

This represents the maximum configurable time, assuming that Interior Gateway Protocol (IGP) convergence is expected to be completed across all routers within the update delay.

The loop-free explicit path remains active during this period, following which the post-convergence path takes over.

The following output confirms that microloop avoidance is enabled on router P2:

RP/0/RP0/CPU0:P2#show isis protocol | utility egrep -A2 Micro
        Microloop avoidance: Enabled...