Re: [nsp] Trying to decide on IGP

From: brad (brad@poofy.tbn.tm)
Date: Sun Aug 02 1998 - 20:41:38 EDT


> AFAICT, from looking at the "OSPF Design Guide", summary-address won't
> help me. The situation is that at the main POP I have various access
> servers and routers injecting E2 routes into OSPF in area 0. At the
> remote POP, I'll have an access server or two injecting E2 routes into
> OSPF in area 1. If an access server reboots in area 1, I don't think all
> the routers in area 0 should be notified (via a few subnet routes
> flapping). Similarly, routes flapping in area 0 shouldn't be noticed by
> routers in area 1. In fact, area 1 doesn't need to know about any of the
> subnet routes in area 0 because it's going to default to sending packets
> to RTA in area 0 for anything that's not local.
>
> This is why I was originally thinking of having each POP run OSPF with
> separate area 0's at each POP...and then redistribute OSPF into iBGP at
> each POP's border router.
>
One relatively simple idea is to assign an ospf area per wan city
and then redistribute from those areas into your backbone area
using range to summarize all of the little stuff. You can provide
your backbone router with a coarser level of granularity.

It would seem that you alluded to this idea with your
area 1/area 0. However, it was my impression that summary address
should be used when you are injecting routes from bgp or somesuch
into ospf. When moving between ospf areas, range seemed suited
to the aggregation task.

BR



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