From: Chris Mott (cmott@xxxxxxxx)
Date: Sun Apr 15 2001 - 13:56:46 GMT-3
For redistribution, assuming IGRP (or other DV protocol) into OSPF, there
are two things (among others) to watch for ... I discovered these as I
worked on CCBootCamp Lab 5 ...
1) make sure only those interfaces that are needed for a routing procol are
active ... i.e. use the "passive-interface" command liberally throughout
your lab with all routing protocols ... you cannot go wrong with it,
especially on ASBR's
2) ensure that those routes being redistributed into OSPF are the only ones
required using whatever method you see fit ... for Lab 5 I used a route-map
to filter all but the IGRP routes from being redistributed into OSPF ...
that in conjunction with the passive interface command made the "ip ospf
demand-circuit" command work as specified
the best way to check if there is inaccurate redistribution is to check the
OSPF database for Type-5 LSA's where they should not be, like for directly
attached OSPF areas ... then you'll know that something is afoot
I've never understood the reasoning behind a dialer-list that has "deny ospf
any any", as I thought the whole reason for an OSPF demand-circuit was that
OSPF could bring up the link if a routing decision deemed it necessary ...
please correct me if I'm wrong ...
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Roy Grego
Sent: Sunday, April 15, 2001 12:30 AM
To: Corey M. Ellis
Cc: ccielab@groupstudy.com
Subject: Re: External LSAs keeping ISDN line up!!!
Corey,
1) Have you done a debug to see what is keeping the
Bri line up? (sometimes its not what you think is).
2) Looking in the OSPF database (timers) should point
out which route is being relearned so you can block
it.
3) Get the ISDN line up and let OSPF exchange hellos
then issue the OSPF demand-circuit command. You should
not have to block OSPF is the dialer-list (only
complicates matters worse).
4) Also, these commands will help keep a Bri line
quiet.
no cdp enable
ip opsf-demand circuit
no peer neighbor-route
You can look through the archives for more info on
this topic.
ROY
--- "Corey M. Ellis" <coreye@odigo.com> wrote:
> Hi all,
>
> I know External LSAs keep up the ISDN line even with
> a OSPF-demand circuit.
> And I know if you block ospf in your dialer-list as
> such:
>
> access-list 101 deny ospf any any
> access-list 101 permit ip any any
> dialer-list 1 protocol ip list 101
>
> My question is if your ISDN line is serving as a
> backup to a frame-relay
> connection say between r1<--->r2. when s0 goes down
> the bri0 will become
> the backup line for r1<--->r2. The requirement is to
> still see all the
> routes through the bri0 just like when the s0 was
> up.
>
> If you block ospf, the adjacency won't be made when
> the backup kicks in.
> How do you keep the line quiet, but still have full
> routes when the primary
> interface fails.
>
> Thanks
> Corey M. Ellis
>
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