We have a T1 and a DSL. Both are routed through a CISCO router, such that with a few simple commands, we can direct traffic from our LAN to one or the other connection. If one goes down, we can be back up in under 5 minutes. There's a lot of other complicated routing going on under the hood, such that some traffic uses the DSL all the time.
Ah, that can confuse the tracker. The tracker uses the IP address of the packets to register the peer with the swarm. If you're listening on one address but sent the registration to the tracker out your other address, the swarm can't know how to get to you.
