From: Richard Dumoulin (richard.dumoulin@vanco.es)
Date: Mon Jul 12 2004 - 11:44:10 GMT-3
Yes but once ospf has synchronised, demand circuit will not maintain the
call, dialer watch will.
--Richard
-----Original Message-----
From: ccie2be [mailto:ccie2be@nyc.rr.com]
Sent: lunes, 12 de julio de 2004 15:51
To: akbar khan; cccie71@yahoo.com; ccielab@groupstudy.com;
security@groupstudy.com
Subject: Re: OSPF Demand Circuit with Watch List..
I think that if both ospf demand circuit and dialer watch are configured,
the ospf demand circuit will trigger a call first because that happens as
soon as there's a topology change. Dialer watch has to wait until a route
is removed from the route table. But, I'm not sure. In the lab, I would
just try to figure out which of these two methods is being asked for and
configure just that method.
The key to success in this area is to understand how each method works
(including backup interface) and configure which ever method best meets the
lab requirements.
HTH
----- Original Message -----
From: akbar khan
To: cccie71@yahoo.com ; ccie2be@nyc.rr.com ; ccielab@groupstudy.com ;
security@groupstudy.com
Sent: Sunday, July 11, 2004 5:03 PM
Subject: Re: OSPF Demand Circuit with Watch List..
thanks for the clarification...
Tom,
I don't have the config now, in summary I just want to uderstand that, if
there is a ospf topolgy change does the BRI willl overlook the configured
watch-group 1 and trigger the call based on the configured demand circuit.
I know very well that there is no sense of using 2 backup options where
only one is required but their are some exceptions.
Akbar khan
>From: Tom Rogers <cccie71@yahoo.com>
>Reply-To: Tom Rogers <cccie71@yahoo.com>
>To: ccie2be <ccie2be@nyc.rr.com>, akbar khan <ciscokhan@hotmail.com>,
ccielab@groupstudy.com, security@groupstudy.com
>Subject: Re: OSPF Demand Circuit with Watch List..
>Date: Sun, 11 Jul 2004 07:48:50 -0700 (PDT)
>
>ccie2be,
>R U saying if ISDN is running between R1 and R2 and OSPF in between. And
a route is being redistributed from protocol X into OSPF, and that route
goes away, OSPF will not trigger a call?
>
>Akbar,
>Can U paste your config for R1 where U have DC and Dialer watch
configured on the same router?
>I hope you're aware of ospf should an interesting traffic for DC and
unintersting for dialer watch.
>
>Tom
>
>ccie2be <ccie2be@nyc.rr.com> wrote:
>Hi Akbar,
>
>I have thought about the same thing not so long ago.
>
>Here's how I understand this.
>
>In many respects, these 2 commands are functionally redundant - in other
>words, they accomplish the same thing but use different methods to do so.
>
>That said, I can imagine there are situations where you have to use
dialer
>watch instead of ospf demand circuit. One possible situation is where the
>watched route isn't an ospf route. I've never actually seen this
situation,
>but here's my thinking.
>
>ospf demand circuit will trigger a call only when there's a change in the
>ospf topology. But, suppose dialer watch is configured to watch a route
>that isn't an ospf route or a route redist into ospf. In this case, the
>ospf topology might not change so with ospf demand circuit configured, a
>call is NOT triggered. But, with dialer watch configured, a call is
>triggered if the watched route disappears from the route table.
>
>Again, let me emphasize that I've never actually seen a network where
dialer
>watch would work but ospf demand circuit wouldn't work, but I can imagine
>Cisco could design a lab in which this could be the case.
>
>However, if the network is a pure ospf network, then I believe either
method
>would work and there would be no reason to configure both. But, if you
were
>configuring dialer watch to trigger the isdn circuit, then you would need
to
>make sure ospf traffic was defined to not be interesting traffic because
>otherwise the ospf hello's would keep bringing up the isdn circuit.
>
>I would certainly be interested in knowing if others have a different
>opinion.
>
>HTH, Tim
>
>
>----- Original Message -----
>From: "akbar khan"
>To: ;
>Sent: Saturday, July 10, 2004 1:52 PM
>Subject: OSPF Demand Circuit with Watch List..
>
>
> > Hello Folks, Is it reasonable to use dialer watch-list with Demand
> > Circuit. Ex: R1---ISDN---R2 & R1----FR----R3-----FR----R2 (Hub &
> > Spoke) running OSPF on all the links. I have configured R1 BRI for
Demand
> > circuit to fire for any ospf topology change. In addition I am
watching
> > the Loopback of R2 with watch list. My question is that if there is a
> > toplogy change somewhere in the ospf domain except the loopback of R2
> > does my R1 will trigger the call with the stipulaiton that it is
already
> > configured with watch-list.. I mean can my BRI will trigger the call
for
> > both topolongy change or in the loss of R2 Loopback...? Many thanks
and
> > Regards in Advance, Akbar khan
> >
> >
------------------------------------------------------------------------
> >
> > Add photos to your messages with MSN 8. Get 2 months FREE*.
> >
> >
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