Cisco Support Community
Community Member

How do i Configure ISDN backup for EtherNet0/0 on 3725 Router.

Hi Guys !

I have a Cisco 3725 Router with 2 ethernet interfaces and 4 BRI S/T interfaces. Ethernet0/0 is connected to Internet and Ethernet0/1 is connected to my LAN. I want to configure DDR so that whenever internet link via Ethernet0/0 is down router may automatically establish Backup link via ISDN dialup interface.

Solution, that so far, I have found is " Reliable Static Routing Backup Using Object Tracking " ......but I think this future is not available in 3725 router. Because when I try to configure this future as per directed in the manual, key commands are not availabe in my Router's IOS. My router is using " IOS (tm) 3700 Software (C3725 ADVIPSERVICESK9-M), Version 12.3(5a), RELEASE SOFTWARE (fc1) "

Please suggess me how do I configure DDR in my network scnario.

Waiting for your Warm & Quick response.


Community Member

Re: How do i Configure ISDN backup for EtherNet0/0 on 3725 Route

Pls try using floating static route pointing to BRI interface and default route pointing to Ethernet0/0.

Whenever your Ethernet0/0 goes down, default route will get shift to BRI interface.

This will generate interesting traffic on to BRI interface and BRI will dial and connect to ISP POP.

CreatePlease to create content