From: Edwards, Andrew M (andrew.m.edwards@boeing.com)
Date: Thu Aug 25 2005 - 14:46:57 GMT-3
Sure. Just remember two dialer watches is an OR operator, one dialer
watch is an AND.
Or you can get really creative as per marvins posting as well. 8)
-----Original Message-----
From: Gustavo Novais [mailto:gustavo.novais@novabase.pt]
Sent: Thursday, August 25, 2005 2:23 AM
To: Edwards, Andrew M; ccielab@groupstudy.com
Subject: RE: Dialer backup without demand circuit
Hello
I thought it wasn't possible to have two dialer watch-groups on the same
BRI...
I tried it... And it IS!!
That solves my problem! (I was using two backup interfaces, with rtr
probes to trigger the link)
Thanks for the little push! :)
Gustavo
-----Original Message-----
From: Edwards, Andrew M [mailto:andrew.m.edwards@boeing.com]
Sent: quinta-feira, 25 de Agosto de 2005 0:16
To: Gustavo Novais; ccielab@groupstudy.com
Subject: RE: Dialer backup without demand circuit
Gustavo,
Have you considered using two dialer watch settings?
HTH,
andy
-----Original Message-----
From: Gustavo Novais [mailto:gustavo.novais@novabase.pt]
Sent: Wednesday, August 24, 2005 1:26 PM
To: ccielab@groupstudy.com
Subject: Dialer backup without demand circuit
Hello group
I'm doing an exercise where I have a setup speaking OSPF
R2---FR---R4
| |
ISDN FR
| |
R5---FR---R6
|
R7
I'm told the following:
Configure ISDN link between R2 and R5 in the same area. Configure these
routers such that OSPF hello messages do NOT bring up the link, do NOT
use ip ospf demand circuit to accomplish this task.
Configure R5 such that if FR link to R6 and/or the ethernet link to R7
goes down it will automatically bring up ISDN and have full conectivity
to all networks
My guess initially was to deny ospf packets on dialer-list of R2 and R5,
to the first part. I tried ip ospf flood reduction to see if I could
maintin neighborship up as with demand circuit, but tests showed that ip
ospf flood reduction didn't suppress hellos as on demand-circuit does,
so neighborship R5-R2 went down, but that would be fine according to the
question.
I'm left to two options for the second part.
ONE - I thought about dialer-watching routes from R6 and R7. The
problem is that dialer watch does a AND (all watched routes must be
down) and I need a OR of the routes. (LOGIC OR one, other or both)
So, no dialer-watch here.
TWO - backup interfaces - I can configure BRI as backup of both Serial
to R6 and ethernet to R7. That would work, IF I still allowed OSPF
hellos to be interesting traffic crossing the ISDN. The backup interface
is activated when Serial OR Ethernet go down. The problem is that I do
not have interesting traffic to trigger ISDN link and maintain it up, so
I'm dead...
Am I missing something? Is the exercise impossible? Perhaps if I define
some kind of RTR probe that matches interesting traffic when ethernet or
serial are down...
Any help is welcome...
Thanks
Gustavo
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