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New Member

OSPF type 5 filtering

hi folks,

is there any way to filter OSPF type 5 LSA?

please help.


New Member

Re: OSPF type 5 filtering

Type 5's are external routes so the best way to filter is on the ASBR that is redistributing them. Put a route-map on the redistribution - easy.

If you want the majority of OSPF routers to know about an external but you want one single router not to that is more difficult. As I understand it distribute listing on OSPF actually filters out entries from the LSA as they are received. You obviously don't want to attempt this on anything internal to an area - disaster! - but it should work OK for externals as these are distance vector routes anyway, its not critical that all databases have them the same.

If you have one area that you don't want routable to a particular external its probably much less dangerous to block it by access-list, or blackhole it with a local static to null0.