Contrail Version : 21.4.L3.555
vRouter Agent CoreDumps. And vRouter Agent Restarts.
Core file be generated in /var/crashes directory.
There is a particular condition in contrail version 21.4.L3.555, which is fixed in 21.4.L4.1
Due to this condition, certain objects can become stale in vRouter Agent. For example : vrouter agent did not retract type 5 routes in a LR VRF. This scenario will trigger stale entries and further causes vRouter to crash dump.
Upgrade to 21.4.L4.1 will fix the problem.
Note : If you need to confirm the crash is due to this know issue, you will need to create a JTAC case with the core dump attached.