Symptom

On doing RP switchover on rack1 of a NCS6K multichassis system, after the new standby has booted up, it is seen that BGP NSR is temporarily disabled on some of the ipv6 and vpnv4/v6 neighbors. The NSR state goes from NSR-ready to "TCP Oper Down" for 2-3 minutes as seen in "show bgp ipv6 unicast summary nsr". After 2-3 minutes, bgp beighbors go back to nsr-ready status. Following messages are seen when bgp nsr is disabled - %ROUTING-BGP-5-NBR_NSR_DISABLED_STANDBY : NSR disabled on neighbor on standby RP due to Routing Table process not responding %ROUTING-BGP-3-NBR_NSR_DISABLED : NSR disabled on neighbor due to Standby reset

Conditions

This is seen on doing a RP switchover on a particular rack of NCS6K multichassis system. This issue is not expected to be seen on a NCS6K singlechassis system.

Workaround

Wait for ~3 minutes on seeing the below message, all affected bgp neighborship go back to nsr-ready after that duration - %ROUTING-BGP-3-NBR_NSR_DISABLED : NSR disabled on neighbor due to Standby reset

Further Problem Description