Routing table problems include but are not limited to:
inactive routes
unnecessary routes
black hole routes
Note
Only black hole routes that belong to the static type protocol are supported. An inter-VRF black hole route is not installed in the routing table of the destination VRF on the same switch.
flapping links (links that go up and come down) that cause the routes to flap
incorrect route tables
invalid Address Resolution Protocol (ARP) cache that causes incorrect IP to MAC assignment
problems with administrative distance or other parameters
Important
Do not restart a device to clear a problem. In restarting the device, you also clear the logs. Logs are vital and can help determine many problems.