From: Brian Dennis (brian@xxxxxx)
Date: Mon Aug 19 2002 - 17:01:46 GMT-3
If you have no interesting traffic defined on the remote router what
will stop him from dropping the line after 120 seconds even if the local
router has data to send? 120 seconds is enough time to allow routing
updates but the line will never be up for more than 120 seconds. In the
real world this would create problems by having the line constantly go
up and down. Try and download a large file when this is happening ;-)
Check out some of the dial backup examples on CCO. You'll see that it is
normal to just leave off the dial string on the remote router.
http://www.cisco.com/warp/public/793/access_dial/backup_11047.html
http://www.cisco.com/warp/public/793/access_dial/bri_isdn_11049.html
http://www.cisco.com/warp/public/793/access_dial/britobribackup.html
The high idle timeout on the remote end is just a "stupid lab trick" if
the question didn't allow the use of the dialer-list command.
Brian Dennis, CCIE #2210 (R&S/ISP Dial)
-----Original Message-----
From: kasturi cisco [mailto:kasturi_cisco@hotmail.com]
Sent: Monday, August 19, 2002 12:34 PM
To: brian@5g.net; brian@cyscoexpert.com; ciscoworks2001@yahoo.com;
ccielab@groupstudy.com
Subject: RE: Backup Interface and IGRP
Brian,
If i understand u right - are u saying that its better to have no dial
string rather than "no dialer list" . what problem might it create ?
Also why do u say very hi idle timeout ? i thought the idle timeout
should be same on both sides. So if the idle timer expires on the local
(calling sisde) then when the timer expires it drops the line, right ?
even if its 120 secs the updates would be exchanged and it would work.
Am i getting confused ?
Kasturi.
>From: Brian Dennis
>To: 'Brian McGahan' , 'kasturi cisco' , ciscoworks2001@yahoo.com,
ccielab@groupstudy.com
>Subject: RE: Backup Interface and IGRP
>Date: Mon, 19 Aug 2002 11:38:51 -0700
>
>If you don't have a dialer-list you need to take into account that the
>remote router will not have any interesting traffic. If the local
router
>with the backup interface command makes an ISDN call, the longest the
>line will be up is 120 seconds due to the fact that the remote router
>doesn't have any interesting traffic and is dropping the line when its
>idle-timeout expires. I would suggest just not giving the remote router
>a number to call or at least adjusting the dialer idle-timeout to
>something really high.
>
>Brian Dennis, CCIE #2210 (R&S/ISP Dial)
>
>-----Original Message-----
>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
>Brian McGahan
>Sent: Monday, August 19, 2002 10:35 AM
>To: 'kasturi cisco'; ciscoworks2001@yahoo.com; ccielab@groupstudy.com
>Subject: RE: Backup Interface and IGRP
>
>Kasturi,
>
> Not a restrictive dialer-list, *no* dialer-list. If the local
>interface is in standby mode, there will never be a circumstance that
>the remote side is allowed to dial in. Even if it does dial in, the
>local side will not answer since the interface is in standby.
>
>Brian McGahan, CCIE #8593
>Director of Design and Implementation
>brian@cyscoexpert.com
>
>CyscoExpert Corporation
>Internetwork Consulting & Training
>http://www.cyscoexpert.com
>Voice: 847.674.3392
>Fax: 847.674.2625
>
>-----Original Message-----
>From: kasturi cisco [mailto:kasturi_cisco@hotmail.com]
>Sent: Monday, August 19, 2002 12:30 PM
>To: brian@cyscoexpert.com; ciscoworks2001@yahoo.com;
>ccielab@groupstudy.com
>Subject: RE: Backup Interface and IGRP
>
>Armand,
>
>Looks like the IGRP traffic is the interesting traffic from remote end.
>As Brian wrote since there is no need for this traffic to dialin deny
>this traffic at the remote end. Create a restrictive dialer list and
>deny this traffic - may be dialer list 1 deny igrp any any or may be ip
>any any ?
>When u deny this traffic it wont dialin. There wont be a need as u are
>using backup interface so when the local side (side where backup
>interface cmd is placed) has physical interface in down state it will
>dial out and establish connection.
>Am i right ? this should work as u say snapshot routing is not
>allowed.Which case study is this ?
>Let us know.
>
>Good Luck,
>Kasturi.
>
> >From: "Brian McGahan"
> >To: "'Armand D'" , "'kasturi cisco'" ,
> >Subject: RE: Backup Interface and IGRP
> >Date: Mon, 19 Aug 2002 11:30:28 -0500
> >
> >Armand,
> >
> > Don't put interesting traffic on the remote side. Assuming this
> >is only a point-to-point dial scenario, and the local side is in
>backup,
> >there will never be a case where the remote side should be dialing at
> >all.
> >
> >Also, "debug dialer packet" will give you more detailed information
> >about what traffic is interesting or not.
> >
> >
> >HTH
> >
> >Brian McGahan, CCIE #8593
> >Director of Design and Implementation
> >brian@cyscoexpert.com
> >
> >CyscoExpert Corporation
> >Internetwork Consulting & Training
> >http://www.cyscoexpert.com
> >Voice: 847.674.3392
> >Fax: 847.674.2625
> >
> >
> >-----Original Message-----
> >From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
>
> >Armand D
> >Sent: Monday, August 19, 2002 11:06 AM
> >To: kasturi cisco; ccielab@groupstudy.com
> >Subject: Re: Backup Interface and IGRP
> >
> >Hi,
> >
> >I am prevented from using snapshot and watch-lists.
> >I'm trying to use the backup interfcace so this router
> >only dials when it loses connectivity on its primary
> >port. It appears that igrp brings the call back up
> >from the remote side from the show dialer cmd: Dial
> >reason: ip (s=135.4.35.6, d=255.255.255.255)
> >
> >Is there any way to prevent this call back issue ?
> >
> >Thanks,
> >
> >Armand
> >
> >--- kasturi cisco wrote:
> > > Armand,
> > >
> > > If u look at the debugs (maybe easier in lab to use
> > > the show dialer cmd as
> > > this generates less amount of info than
> > > debug)...gives similiar info for
> > > troubleshooting...The show dialer cmd will show the
> > > dial reason which helps
> > > to find why link is going UP/DOWN
> > >
> > > When u look at the output it shows bcast as dest
> > > address
> > > >
> > > >1w3d: BRI0/0: ip (s=135.4.35.5, d=255.255.255.255),
> > > >186 bytes, outgoing interesting (list 100)
> > >
> > > The router with Src address shown above is
> > > generating IGRP routing updates
> > > and hence these updates. To the best of my knowledge
> > > the ways to do this is
> > >
> > > - if u deny igrp routing updates and use static
> > > routes (may not be a option)
> > >
> > > - USe snapshot routing as this prevents the DV
> > > protcols form sending updates
> > > every "update interval"
> > >
> > > I cant think of any other way ? anyone care to add
> > > ??
> > >
> > > HTH.Are u prevented from using Snapshot ?? by the Q
> > > or Secenario.
> > >
> > > Good luck,
> > > kasturi.
> > >
> > >
This archive was generated by hypermail 2.1.4 : Sat Sep 07 2002 - 19:48:30 GMT-3