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ip route??


What happen if I configure the IP route no entry in routing table but what it happen??    

Please help...

Cisco Employee

Re: ip route??

Hello Abhinay,

Nothing will happen, the route will not be inserted into the routing table because of the following two reasons:

  1. Any route that recursively loops back to itself, either directly or over a set of different routes, will be removed from the routing table. There is a process in IOS that checks the routing table every minute, and if a recursive routing entry is detected in the routing table, it will be removed. Your route is recursively looped into itself directly - the next-hop IP address of this network is inside this very network.
  2. For every route that is defined using the next-hop IP address, the next-hop IP address must be resolvable in the routing table, otherwise the next-hop IP is considered unreachable and the route will be declared unusable. However, a default route will never be used to resolve a next-hop IP address. In other words, there must be a more specific match for a next-hop IP address in the routing table than the default route. As the only reasonable match for the next-hop IP address can be the default route itself, no other entries in the routing table will match. As a result, the next-hop IP address is considered unreachable and the route cannot be inserted into the routing table.

Best regards,


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