Comment 1 for bug 1351243

As per current contrail-vrouter-agent design on restart it resets vrouter(kernel dataplane module) and starts reprogramming as and when it starts receiving config and routes, to keep vrouter and vrouter-agent always in Sync.

because of this on vrouter-agent restart, vrouter will not have forwarding information for a short while and will result in drops/traffic loss.

To Achieve graceful restart of vrouter agent we need to have a mechanism to read back forwarding plane information from vrouter and then should be able to audit and cleanup the stale information.