routing between two internet access lines
if you have two networks in same building.
both of them have seperate DSL modem and ISA servers and different IP schema.
incase if you want to make a redundancy.
how can we do the design so if Modem-1 was down, Modem-2 will take the role.
initially if both modems are working fine, then no need for backup. just let them work as they are (separately).