route Maps with OSPF for set ip next-hop


3845 router with multiple Virtual Tunnel Interfaces facing the Internet and two Interfaces facing a PIX firewall.

Need: Routes to certain tunnels must be available from the PIX via a specific interface (one of the two).

Question: Can a route map be used with the outbound LSAs to specify the next hop that the PIX knows about ? In other words, I want to run a route map on the 3845 that sets the "ip next-hop" that is advertised into OSPF.

For example, the PIX would then know that network /24 is available via interface G0 on the 3845 router and network is available via interface G1 on the 3845 router.

Note that I can make this happen by running 2 OSPF processes on the PIX and the router, but I would prefer to do it with route maps. Both interfaces on the 3845 router can be in the same area or different areas, whichever is necessary to make this thing work.

Bottom line, can route maps with the set ip next-hop command be used to control the information that an OSPF participant receives?

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If the question is can outbound LSA's be modified using route maps, AFAIK this is not possible.

There is now the ability to perform OSPF ABR Type 3 LSA Filtering - see

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If you ran BGP between the 3845 and the PIX, then doing what you want to do is easily accomplished by setting next hop via a BGP outbound route map.

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I would think that such LSA filtering as requested by the OP would violate the OSPF architecture.

OSPF does not advertise routes or next hops between routers, it instead sends information about the network topology. Every router in an area has the same information about the topology from which the next hops are (routing table entries) are determined. It is an absolute requirement (in order to avoid loops and provide reachability) that every router in an area has the same topology database and so filtering would not be possible.

Between areas and between routing processes then things are different.

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