Backup configuration

[WILLIAM STEGMAN]

I'm trying to implement a backup solution for my Internet connection. Right now, I have all my Internet bound traffic going to my Comcast Internet connection through a PIX which is connected to my Cisco 2811 router's fa 0/1. My WAN traffic is headed out a serial T1 connection. Our Atlanta office has an Internet connection that we use as a backup. The current config goes like this.

All WAN traffic is forwarded out the WAN interface, and the default route 0.0.0.0 0.0.0.0 is pointing to Comcast. A static floating route exists that points to the WAN interface, so if I unplug the fa 0/1 (router to PIX connection) all the traffic that would normally go to Comcast, is now re-routed to Atlanta and the Internet successfully. However, the problem is when I take the Comcast cable modem down, the 2811 still sees the fa 0/1 interface as up and forwards Internet bound traffic its way, which of course is now a dead end. I've looked at HSRP, but it seems like that wouldn't work here since it involves making 2 gateways appear as one. I want Internet bound traffic to head toward Comcast unless it is down, and of course I can't send WAN traffic toward Comcast. Does anyone have any ideas for this scenario?

Thank you,

Bill

[thisisshanky]

You can Use RTR and Track feature to monitor if Comcast gateway is down.

ip route 0.0.0.0 0.0.0.0 track 9

##### Default route via Comcast network.

ip route 0.0.0.0 0.0.0.0 serial 0 150

##### floating static route.

rtr 1

type echo protocol ipIcmpEcho

timeout 1000

frequency 3

threshold 2

rtr sched 1 start-time now life forever

!

track 9 rtr 1 reachability

Here is a link to more info on the commands.

http://www.cisco.com/en/US/products/sw/iosswrel/ps5207/products_feature_guide09186a00801d2d74.html

HTH

PS: please remember to rate helpful posts.

[WILLIAM STEGMAN]

I only got to test this today, but wanted to say it works great. Thank you very much.

Bill