Filter OSPF hosts

Unanswered Question
Jul 17th, 2008
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Whe have ospf processes on ours routers

router ospf 1


area 0 authentication message-digest

network X.X.X.X X.X.X.X area 0

network Y.Y.Y.Y Y.Y.Y.Y area 0

distribute-list 80 in

access-list 80 permit Z.Z.Z.Z Z.Z.Z.Z

access-list 80 deny any log

and "distribut-lists" to filter some network.

We want to filter some "hosts" rather than networks

When we use "access-list 80 permit host Z.Z.Z.Z" the route does not appear

thank you very much for your help

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lee.reade Thu, 07/17/2008 - 04:59
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Are you saying that you dont want to accept routes from some ospf neighbours?

Or dont want to form ospf adjancencies with some neighbours?

Or are you asking that you dont want to allow some networks into the routing table?

If you could let us know.



Edison Ortiz Thu, 07/17/2008 - 05:41
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In order to filter that IP address, that IP address must be in the routing table.

You can't pick a network route entry and block just a portion of the network and allow the rest. The host or network entry must be in the RIB in order to match the ACL.

BTW, ACLs in OSPF are not recommended as OSPF will block the routes from entering the routing table but OSPF will still keep the LSA on its database (show ip os data to confirm). In other words, if you are connected to another device, they will receive your LSA information and the route(s) you just blocked will appear in their routing table.




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