From: Scott Young (syoung@xxxxxxx)
Date: Tue May 08 2001 - 20:15:15 GMT-3
It is true that you can use dialer watch for this scenario, but my
experience with testing it just now is that OSPF continues to bring up the
link when the topology changes. It seems that the watching router still
needs to send an LSA to its neighbor on the other side. Therefore, dialer
watch by itself doesn't really fulfill the requirement of "...The ISDN
connection should only come up if the ethernet connectivity is broken..."
What else is missing? Or is the question just badly worded?
Scott
-----Original Message-----
From: McCallum, Robert [mailto:Robert.McCallum@let-it-be-thus.com]
Sent: Tuesday, May 08, 2001 11:05 AM
To: 'K. Radecki'; ccielab@groupstudy.com
Subject: RE: ccie bootcamp lab 8
The question specifically asks you to make sure that the ISDN line only
comes up by the failure of the Ethernet interfaces. Clue both the Ethernet
interfaces are in the same subnet / network.
Is there a way to "watch" for the disappearance of that network????
-----Original Message-----
From: K. Radecki [mailto:kradecki@yahoo.com]
Sent: 06 May 2001 02:41
To: ccielab@groupstudy.com
Subject: ccie bootcamp lab 8
I've copmlete lab 8, but still have an issue with
Section 2 Task 3 Part 1. It states "...The ISDN
connection should only come up if the ethernet
connectivity is broken..."
I have the IDSN link configured as an ospf-demand
circuit, so Hellos and periodic updates don't keep the
line active. Also, I've filtered IGRP from
redistributing OSPF-learned routes back into OSPF, so
there's no issue there. The problem I'm having is that
the line comes up as soon as the there's a topology
change in OSPF, ie I take down an interface in the
network that OSPF advertises, even if the ethernet
network is active.
Based on the way ospf demand-circuit works, that
doesn't surprise me. And, in a stable OSPF network,
the link never comes up. Does the task assume a stable
network? The way I read it, it doesn't. But, I don't
know how to keep the link from activating using just
demand-circuit. And, in the configuration they provide
as the solution, they only use ospf-demand circuit.
Thanks,
Kurt
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