OSPF Questions

[tschimmel]

I have an issue with OSPF. We have an area 0 and 1 and 2. 1 and 2 both connect to 0 via tunnels. Since 1 and 2 both connect to the backbone this is fine at the moment, but we are being pushed to put a wireless link between 1 and 2 to pass a portion of the traffic from 1 to 2. I have recommended putting making 1 & 2 just 1. They are withing 20 miles of each other and have all the same requirements. Also, we will add passive interfaces and some route maps. Ugh. Can we do this without the area change? All OSPF white papers suggest "NO". All input welcome!

[m.gamal]

sir

as far as i understand..u want to pass some traffic from area 1 to area 2 without changing areas..right??

well if this is so , may be you can add static routes on the link between the two areas, for just the traffic directed from an area to the other.

this will not change areas.

wish i could help

[ruwhite]

The only way at the moment would be some statics or another protocol, redistributed in, with filters are the ABR to block the routes from making it back into area 0. I thought there was a feature coming to fix this, but I've looked around some, and can't seem to find it.

Probably the easiest way to do this is to use another ospf process, redistributing into the new ospf process from the current one, and redistributing back into the current ospf process from the new one. It sounds like you would only have one point of redistribution, on either end of the new wireless link, so you really shouldn't need to worry about tagging the routes to prevent a routing loop with the mutual redistribution.

But you do want to filter these externals so they don't make it into area 0 (unless you want to use one area as a back for another area). It might be easiest to tag the routes as they are redistributed into the original ospf process, so you can filter based on those tags at the ABR into area 0. If you need help with a sample configuration, post here, and I can work something up in the lab.

Russ.W