Can someone give me the basic configuration steps to load balance two T1's? It is on a 1700 series router.

Answer 1

If you have 2 T1s coming into your 1700 series router, they should load balance automatically. The maximum-paths setting is 4 paths by default with a maximum of 6 paths. So assuming the routing protocol you're using gives two equal cost paths (one over each T1) then the router will automatically load balance these. You'll also want to look at if your want to do per-packet or per-destination load balancing, which can be accomplished with the interface commands "no ip route-cache" and "ip route-cache" respectively. If the paths are NOT equal cost, then you would need to run IGRP or EIGRP and configure the variance setting to allow unequal cost path load balancing. Also check out the design technote (link below) on IP routing load balancing.