From: Tracy Blackmore (TracyB@xxxxxxxxx)
Date: Mon Jan 29 2001 - 18:59:54 GMT-3
The demand circuit does not suppress LSA's. It only suppresses the hellos
and the Link aging (in turn suppressing the periodic LSA refresh.) With the
demand circuit, the router will dial immediately to establish neighbors and
update it's Link Database and then go quite until a LSA occurs. Keep this
in mind when redistributing other routing protocols as they will generate
LSA's in your OSPF area.
Tracy W. Blackmore
T.S. Lad Consulting
1026 E Stanford Ave.
Gilbert, AZ., 85234
(480)558-0472
-----Original Message-----
From: Mike S. Lee [mailto:mikele@cisco.com]
Sent: Monday, January 29, 2001 2:38 PM
To: Kevin Baumgartner
Cc: Wade Edwards; ccielab@groupstudy.com
Subject: RE: ISDN Backup without the backup interface command?
In trying to use the Demand circuit option I still see the dialer dialing.
Debugging Q931 is see that the dial cause is 224.0.0.5 which is all spf
routers. I thought that using an ospf demand circuit should have suppressed
all LSA's from going across this line. Can someone either explain this
behavior or provide a working config that uses demand circuits and only
comes up when the primary link fails? Any debug outputs would be helpful as
well.
thanks
mike
At 11:53 AM 1/29/2001 -0800, Kevin Baumgartner wrote:
>I have heard this a few times but I have had no problems using it with
OSPF.
>Maybe this was a limitation in earlier 12.0 images.
>
> Kevin
>
>
>At 01:18 PM 1/29/01 -0600, Wade Edwards wrote:
> >As I recall dialer watches work only with IGRP and EIGRP. If you need
OSPF
> >then the demand circuit is the best way to go.
> >
> >-----Original Message-----
> >From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> >Jeremy Gray
> >Sent: Sunday, January 28, 2001 2:34 PM
> >To: ccielab@groupstudy.com
> >Subject: RE: ISDN Backup without the backup interface command?
> >
> >
> >
> >A demand circuit is useful if you really msut run OSPF over an ISDN line.
> >
> >A better answer to this problem is to use a dialer watch-list, a very
cool
> >facility used to trigger DDR when a 'watched' route is absent in the
routing
> >table.
> >
> >This is great for a number of reasons.
> >
> >1) Packet switched networks are not the best at telling a DTE when
there's a
> >problem in the cloud. Examples being ATM and FR
> >Interface may stay up/up even if the remote is down.
> >
> >2) You can place a DDR in a place further into your network rather than
on
> >the same router as a critical link and still have DDR work when the link
> >fails if the routes being watches originate beyound the point of failure.
> >
> >Regards,
> >
> >Jeremy.
> >
> >PS: Joined today. Lab date March 8th.
> >-----Original Message-----
> >From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> >Robert DeVito
> >Sent: 28 January 2001 16:39
> >To: obuba@bellatlantic.net; mac38456@pegasus.cc.ucf.edu;
> >ccielab@groupstudy.com
> >Subject: Re: ISDN Backup without the backup interface command?
> >
> >
> >
> >
> >Another thing to keep in mind is that ospf demand circuit will cause the
> >isdn circuit to come up when there is a topology change.. So don't be
> >shocked when it comes up every once and awhile.
> >
> >Robert
> >
> >----Original Message Follows----
> >From: "Nnanna Obuba" <obuba@bellatlantic.net>
> >Reply-To: "Nnanna Obuba" <obuba@bellatlantic.net>
> >To: "Miguel A. Ciena" <mac38456@pegasus.cc.ucf.edu>,
> ><ccielab@groupstudy.com>
> >Subject: Re: ISDN Backup without the backup interface command?
> >Date: Sun, 28 Jan 2001 10:10:43 -0500
> >
> >That's no trick, use ospf demand circuit
> >
> >
> >Nnanna Obuba, CCIE # 6586
> >www.nantech.com
> >Online lab for CCIE Preparation
> >----- Original Message -----
> >From: "Miguel A. Ciena" <mac38456@pegasus.cc.ucf.edu>
> >To: <ccielab@groupstudy.com>
> >Sent: Sunday, January 28, 2001 9:07 AM
> >Subject: ISDN Backup without the backup interface command?
> >
> >
> > > Between R3 and R5 I got a ISDN link. I want to configure my ISDN to =
> > > back-up my frame relay connection between R3 and R5...Here is the
Trick:
> >=
> > > Without using Floating Static and without using the Back-up interface
=
> > > command..My Frame and ISDN are in OSPF area 0...
> > >
> > > any ideas..
> > >
> > >
> > >
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