Symptom
The setup may show either IP-TCP_NSR-3-OUT_OF_SYNC messages or init-sync timeout messages from the applications (BGP or LDP) when the system gets into this state.
Conditions
One of the conditions that causes these messages to appear is when TCP has a stale packet in its NSR retransmission queue. Due to this bug, TCP may continue to repeatedly process the same invalid packet, thereby delaying NSR init-sync (or in rare cases preventing NSR from being achieved).
To confirm the problem please check the packets held by TCP and whether they have been held for a long time. Typically, packets are not held by TCP for more than a few seconds.
show packet-memory inuse should show the packets (identified by their hex-based pakhandles) in use by various processes.
If there are packets accounted against TCP, please use show packet-memory pakhandle to look for details, including the "In use since" data.
Recovery:
If the router doesn't recover by itself, try disabling the NSR for all TCP clients and enable them back one by one.
If the above step doesn't recover the problem, TCP process will need to be restarted on the active node. Note that this will
cause the sessions to go down.
