OSPF Filtering with Route-Maps


wondering why we cant use and extended access-list to specify the source of the route and the actual route to be filtered?  I have tried this and it doesnt take, I just dont understand why - this works for EIGRP.  The solution uses standard access list specifying the ip next-hop to id R4 as the source.

Im mean something like this:

On R5:

router ospf 1

 distribute-list route-map R4_IN in

ip access-list extended R4

access-list 100 permit ip host

route-map R4_IN deny 5

 match ip address 100

route-map R4_IN permit 10



  • Thanks for your reply.  What I was trying to achieve with this was to prevent the network from being in the routing table of R5 if it came from the source of, or in other woirds R5's neighbor on that link.  I understand that the databases need to be the same, however from the solution to this, they are using standard access lists to identify the route source (next-hop) and the route to filter out.  I was wanting to know why we can use an extended access-list to do the same thing, or if my syntax is wrong?

  • Try changing your source IP in your extended ACL to the router-ID of R4 and see what you get.

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