Symptom

Traffic from VRRP client to VMAC is dropped after RPSO. This traffic drop continues until recovery options performed. The following ping patterns failed. 1.Ping with VIP as source address from the VRRP Master 2.Ping with VIP as destination address from the VRRP Client or VRRP backup router

Conditions

VRRP is configured on sub interface and VRRP state is VRRP Master. In the above condition RPSO cause this issue. It occurs with a probability of about 50% when RPSO is performed. The trigger confirmed is RP switchover following module reload. reload / redundancy switchover on XR VM was not able to reproduce the issue. The interface replication behavior specific to NCS560 played some role for the high visibility on the platform, but fix is applicable to all DNX.

Workaround

Delete and reconfigure VRRP settings can be recovery workaround for the issue. Having "hw-module vrrpscale enable" config can be workaround to prevent the issue. Reference. The following were tried but did not WA. - RP switchover - process restart vrrp - I/F shut/no shut

Further Problem Description