Issue seen in upgraded setups from 21.4L2 to next releases like 21.4.L3 or 21.4.L4. Specific VNs / networks are not sending and receiving routing information from controllers. RT only shows local routes .Though, contrail-status .is fine, the RD value for these VNs/network shows -1, for example : 192.168.122.11:-1

Contrail vrouter agent will not send and receive routing information from contrail controllers for these particular networks with -1 RD value. RT only shows local routes.

A DB resync is required to fix this issue from 21.4.L3 onwards, as the RD value is calculated and then programmed onto vrouter agent by config module,

Steps :

1. Login to zookeeper container(docker exec -it config_database_zookeeper_1 bash)
2. Go inside directory bin(cd bin)
3. Connect to zookeeper(zkCli.sh -server <controller-ip>:2181)
4. deleteall /vnc_api_server_locks/
5. quit and exit from zookeeper container
6. Restart Config API server container
7. Restart Control container(docker restart control_control_1)

NOTE : The above steps are service effecting and should be done in a maintenance window. Ensure latest backup of the config database is available. Reach out to JTAC for validating the symptoms and solution if not sure.