From: Marc Russell (mrussell@xxxxxxxxxxxxxx)
Date: Sun Sep 17 2000 - 22:46:21 GMT-3
The issue here is primarily with router r5, but could be router r6 also,
if you redistributed connected on that router.
Router R5 is ruining both IGRP and OSPF and is mutually redistributing
here. The network 137.20.0.0 on IGRP also covers the ISDN interface.
Every time the ISDN link idle-timer ends and the link goes down IGRP
sends this info back into OSPF. You need to filter the IGRP to OSPF
redistribution such that the network on the ISDN link isn't sent into
OSPF. You may have to also filter the route redistribution on R6 also if
you used redistributed connected.
This setup will work without any "no peer neighbor-route" commands.
Hope this helps.
Marc Russell
www.ccbootcamp.com
-----Original Message-----
From: Maljure, Sanjay [mailto:smaljure@cibernetworks.com]
Sent: Sunday, September 17, 2000 9:03 PM
To: CCIE Group Study (E-mail)
Subject: How to keep the ISDN line down (Lab 8)
Hi
Ok It is the timeless question of "how to keep the ISDN line down in lab
8?"
This is what Marc Russels web site has to say...
Quote
Question: I can't keep the ISDN lines quiet with the OSPF demand-circuit
setup. What am I doing wrong here?
Answer: You probably have a problem at one or two points of
redistribution.
On R5 that is mutually redistributing IGRP and OSPF are you filtering
IGRP
into
OSPF such that it doesn't contain the subnet on the bouncing ISDN link?
The
same issue may apply to R6 if you are using redistribute connected.
Unquote
Now I do NOT have elaborate access-lists (while redistributing into
OSPF) on
R5 to accept only required subnets from R4 via IGRP.
I have debug IGRP running and I see that the IGRP update coming in from
R4
has only 1 route which is the ethernet of R4. This makes sense to me
because
I have split-horizon enabled on R4.
So why is my line still flapping all the time??? I infact do not
understand
why we would need the "no peer neighbor-route" command.
I put in the "no peer neighbor-route" on R5 and R6 and this keeps the
line
down but only when the Ethernet connecting R5 and R6 is up.
When I disconnect R5 and R6's ethernet connection, even the "no peer
neighbor-route" doesn't help to keep the line down...
I think the nation deserves an explanation ;-)
Please help
Sanjay
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