can you specify ospf areas per interface ?

[r.dufton]

Hello all,

I have a 2620 which I have set up several seperate dialer interfaces to dial out of a single bri to different parts of our WAN. Each time I dial a location it takes a certain amount of time to relearn the routes for that location and forget what it had learnt from the previous dial in location. At present I only have an area 0. I dont think the way I am going about it is the best at the moment and am worried about the amount of time the routing table is being changed. I was wondering whether anyone knew of a better config for dialling up this way? Perhaps setting up a different ospf area per dial-in ? Can I specify diferent ospf areas to be advertised on different dialer interfaces?

cheers

Richard

[ruwhite]

You can set up different areas on different interfaces, by using the network statement in OSPF. Note that there are wildcard bits in the network statement, so you can use an all 0's wildcard with a specific interface's IP address, and run OSPF in a given area only on that interface. For instance, if you have an interface, 10.1.1.1/24, then you can do this:

router ospf 100

network 10.1.1.1 0.0.0.0 area 44

That would run ospf in area 44 on just that interface.

Now, back to the original question, though--just putting these dial interfaces in a different area isn't going to help much, probably, unless you make that area a stub of some sort, and also summarize ourt of the area into area 0. Otherwise, each route change on a dial link coming up or going down is still going to cause a route change in area 0, through a type 3, at least.

Russ.W

[rjackson]

I never run routing protocols over such small circuits. How many routes are you learning from the remotes? You must have a static route in place now to trigger the calls (since you said it has to forget what it learned from the last call). I'd dump ospf and static route it.