ospf route filtering

[jonk34567]

in eigrp i can filter routers using

1.ip prefix list

2.access list

3.router map 

can i use these 3 ways to filter routers in ospf or is there any separate methods for ospf

[Julio E. Moisa]

Hi

For OSPF you can also use distance with value 255 to drop traffic, example:

router ospf 1
distance 255 <source> <source mask> <ACL>

So the prefixes matched on the ACL and learned by the source will be applied with an AD of 255, then OSPF will discard this prefixes and they will not be included on the routing table. 

Other method is using filter-list, it is used to filter type 3 LSA

AREA <area id> filter-list prefix <prefix-list>

http://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/fiarospf.html

One last fitering method in OSPF is:

OSPF database-fiter, it is used to filter LSAs.

http://www.cisco.com/c/en/us/td/docs/ios/12_2/iproute/command/reference/fiprrp_r/1rfospf.html#wp1018116

Hope it is useful

:-)

[Joseph W. Doherty]

OSPF can route filter, but is limited/different compared distant vector routing protocols.  It would require a lengthy explanation.