I bought a new router (Cisco EA3500) and a Western Digital 2TB hard drive with USB 3.0. The router works fine, and I can use the external drive over the network from multiple machines in the house. But I've just found out that Time Machine isn't "supported" on this router and so I can't do automatic incremental backups. How can that be--if I can read and write from the HD over the network, why does the router care exactly which program on my Mac is sending bits to be written to it? What would a router need in order to be able to support Time Machine?