Can I use a 2524 and ISDN as a backup for a T1 line?

[dgazzane]

Hi all, I need to have a backup connection to the internet in case the T1 line were to go down. I'm not sure how to do this. So here's the setup. I have T1 line to a 1601 router to a hub, to a PIX firewall. I host my web, email, and DNS.

So the question is how or what to use as a backup if the T1 line goes down? I have a 2524 router I'm not using, but not sure what connection type is used for ISDN or if ISDN is the correct thing to do. I'm thinking that if the T1 goes down I connect my PIX to the 2524 and the 2524 has the same IP address as the 1601? I make a connection using the ISDN and life is good, and the PIX doesn't know.? When the T1 comes back I just shut down the 2524 and connect the 1601 backup? Does this sound correct? Can anyone point me in the right direction to get more info or help me with what would work or if the 2524 will work.

Thanks so much for your time.

 

[StarTAC]

the quickest and easiest way would be to have your 1601 have an ISDN-BRI port too.. this way, your users keep that router as their default gateway, for both the T-1 and ISDN connection...

u then configure your serial interface to automatically bring up your ISDN line as soon as it has detected line protocol failure on the WAN circuit...

good luck...

 

[dgazzane]

Thank you StarTAC. Further investigation of the Cisco router shows it's a 1604 and has a ISDN-BRI port, and a ISDN Modem port in it so I am set and can configure the router after the ISDN line is installed.

Now is there a site with tutorials or examples of configurations for these routers or how-to's?

Thanks again.

 

[dredoggg]

if you dont know about Cisco Conig Maker, then download it.
(search google)

Create your setup in that app, then look at the config it generates and you will be able to figure it out.