What you will do if OSPF neighbor flaps and receives the OSPF-5-ADJCHG error message

The Open Shortest Path First (OSPF) neighbors are established by exchanging hello packets at multicast address 224.0.0.5.  If these packets fail due to any Layer 2 (L2) issue, OSPF neighbors flap. This results in the error message ‘OSPF-5-ADJCHG’

To resolve this issue, ensure that the underlying L2 between OSPF neighbors is working properly by issuing the ping command. This ensures reachability to the neighbor address.