basic failover question

[comechivos]

hello,

my question is the following, I have a cisco 2600 router connected to a T1 line and a 30 Mbps cablemodem line, I want the cablemodem as my primary connection and the T1 as my backup connection, when the cablemodem goes down, I want the T1 up and running.

I did this with priorities y the ip route command, BUT when I restart the router, the priorities changes, and when the cablemodem goes down and the T1 goes up I have to configure NAT manually. Im a begginner, so I need your help!!

here is my running config

[comechivos]

is there anyway to put the T1 interface in standby?

when the cablemodem fail. the T1 interface set active. and when the cablemodem is up again the T1 interface goes back to standby mode.

is this possible? because the router is routing against the T1 and I dont want that when the cablemodem is up.

here is my running config