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New Member

Backing up dialer interfaces?

I have one remote router on one site with 1 isdn bri interface, and two routers on a central site which are on the same LAN and have an ISDN interface as well. I want to have a primary isdn link to one of the central routers to gain access to the central LAN and a link to the other central router in a standby mode of some sort, so that if the main link goes down it will kick automatically into the second isdn link.

I've tried 2 dialer interfaces and floating statics but this doesn't work. I've also tried configuring dialer maps under the main bri0 interface and have a static route going to the remote network via a next hop of the bri0 interface but this won't work either.

Cisco Employee

Re: Backing up dialer interfaces?

All you need to have is two dialer strings configured under one dialer interface in the order of which it should be dialed. Meaning you need to configure the 1st dialer string which connects to primary router and other dialer string which connects to secondary isdn router.

With that if primary connection went down OR primary isdn line is no longer available, router will dial the next dialer string which connects to secondary router. Like

interface dialer 1

dialser string 1111

dialer string 2222

Router will always dial 1111 but it will not get CONNECT message at isdn layer is the primary router's isdn lien is down. In that case router will dial 2222 for secondary and it will connect fine.

New Member

Re: Backing up dialer interfaces?

I am trying to do this too. I am right in thinking that this will not work if you have a PRI at the other end. If so , how would you configure in that scenario ?

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