Re: OSPF Filtering question

From: Petr Lapukhov (petr@internetworkexpert.com)
Date: Tue Jul 04 2006 - 14:46:37 ART

Forgot to mention,

this feature is particularly useful in case where you have
shared interface with multiple neighbors. In other cases
you may stick with basic distribute-list functionality.

HTH

2006/7/4, Petr Lapukhov <petr@internetworkexpert.com>:
>
> Just a quick note here,
>
> you may also opt to use "distribute-list with route-map" at R3,
> to filter inbound routes based on next-hop value (or output interface),
> directly at "receiving" router.
>
> http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120limit/120s/120s24/routmap.htm
>
>
> filtering with distance won't work here, since external routes all have
> the same
> advertising RID (route-source).
>
> Everything else should probably use "database-filter" or cost manipulation
> in some
> way (max-metric falls under that category too), to adjust forward-metric.
>
> HTH
>
> --
> Petr Lapukhov, CCIE #16379
> petr@internetworkexpert.com
>
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
> Toll Free: 877-224-8987
> Outside US: 775-826-4344
>
> 2006/7/4, D.H. Williams <draythw@gmail.com>:
>
> > Hey fellows,
> >
> > All right, was tinkering with OSPF filtering last night, and got a few
> > questions and what have not I wanted to ask, to see what everyone has to
> > say. Consider the following situation:
> >
> > R5 with two point-to-point subinterfaces going to R1 and R2.
> >
> > R1 and R2 have hdlc connections up to R3.
> >
> > All of the above links are running OSPF; backend of R5 is running RIP;
> > Mutual Redistribution on R5.
> >
> > Now, let's say I want the following scenerio, I want R3 to get to all
> > the
> > RIP routes (E2) via R1. I tried the distribute-list statement on R2
> > using
> > teh route-map, but this just affects the route table, not the ospf
> > database,
> > so r2 still advertise the E2 routes up to R3, even though they aren't in
> > his
> > routing table.
> >
> > My question, how can I affect R3 to where it prefers R1, including not
> > seeing anything advertise from R2 in the routing table? I'd also like
> > R2 to
> > route through R3 to get to Rip routes. And i'm looking for a solution
> > that
> > doesn't use cost or bandwidth (too easy and obvious, you know).
> >
> > Thanks in advance!
> > D
> >
> > _______________________________________________________________________
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> >
>
>
>
>
> 

-- 
Petr Lapukhov, CCIE #16379
petr@internetworkexpert.com

Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Outside US: 775-826-4344

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