Cable as a backup for T1?

It shouldn't cause any problems as a Backup Line in provided that you have enough security placed onto the Cable connection.

However in the case of the T1 Line falling over you may need to manually reset the servers to send on the Cable Connection. It really depends on the setup and if you and how you are running Exchange as a Mail Client.

Col

45 of the 52 Cisco routers we have at our remote sites are configured just as you described. The Frame Relay ciruit is the primary, secured connection for the WAN, with the cable as a backup. On site, all internet traffic is sent out through cable, and terminal services runs over Frame. It's a simple configuration in the Cisco, to force frame traffic out through cable and vice versa (there have been times, that cable was down, and we pushed internet over frame). Between routing tables and a good firewall, this works great for us:)

You can use a cable as your backup OUTBOUND INTERNET connection at your central site. But it will not help much with your VPN connections to remote sites. I will explain why.

When you create site-to-site VPN link, you configure them with static IP addresses. And you have it configured on the remote sites with IP address of your central site T1. If you T1 goes down, your VPN configuration has to be adjusted with a new IP address of your cable provider IP address. It's possible, but it's a lot of work. Also you didn't tell if you build VPN on your router or on your Windows server. If you have it on the server, you have to reconfigure your static NAT to allow your cable Internet traffic to go to your servers. Again, even thou it's possible, your "manual switching efforts" could be significant.

And now about usind it as an additional line. It's possible, but you have to decide what traffic you will put there. You may, for example, put all your central site users' Internet traffic on this link, but then you will need to modify all your PCs to have different gateways for VPN, remote sites, and Internet.

Good luck,

Mike
CCNP, CCDP, CCSP, CCVP, MCSE W2K, Security+, etc.
http://www.ciscoheadsetadapter.com

Just a note. Cable companys randomly change your IP. Mine seems to change mine about every month or so, but then again, I have seen it change 3 times in a week. So you cannot build scripts to help with changover to cable that rely on a static IP, becuase cable rarely if ever provides static ip. Cable providers offer "buisness" packages that have static i addressing, but at that point why not purchase another T1 and recive the dedicated bandwidth instead of a "maximum" bandwidth package.

You shouldn't have any problems using the cable line . It all depends on how much traffic occurs on that particular line becuase the bandwidth could be used up and cause sluggishness.

I'm trying to accomplish the same thing, I have a T1 that I'd like to backup with a Cable Modem, I'm running up against a wall when I try to find any info on what routing hardware will work best for this.

Can somebody help!?

Ed
ed@silha.com

I'm trying to accomplish the same thing, I have a T1 that I'd like to backup with a Cable Modem, I'm running up against a wall when I try to find any info on what routing hardware will work best for this.

Can somebody help!?

Ed
ed@silha.com