Identify and Remove routes that are not being used

[rdrigues]

Hello,
cisco ISR4451-X/K9
Is there a way that I can identify routes that are not being used to delete?
We have hundreds of routes, and I believe there is a lot of dirt.

[M02@rt37]

Hello @rdrigues,

Use NetFlow or other traffic analysis tools to understand the actual traffic patterns in your network. Unused routes might be identified by low or no traffic.

[Richard Burts]

If we knew more about this environment we could give better advice. So some questions and suggestions would be:

- are these routes static routes or are they learned from some dynamic routing protocol?

- for each route go to the next hop specified in the routing table

-- is the route local to this device or is it remote?

-- if the route is local do show arp and look to see if there are any devices for that subnet in the arp table. If there are arp entries then the route is being used and should not be deleted. If no arp entries then the route is a good candidate for removal.

--  if the route is not local go the the indicated next hop and repeat this process.