segregating computers on a network I've currently got 15 computers plugged into a switch along with a cable modem providing internet access. They all receive their DHCP addresses from the cable modem. I'd like to segregate the computers so they can't get to each other. I thought I'd be able to do this with VLANs, but I'm new to managed switches and I'm having trouble figuring out the configuration. I've currently got a Dell Powerconnect 3524. Any help would be appreciated.

What you want is called "port isolation". Dell PowerConnect switches do this via _Private VLAN Edge_ (PVE). Under the port configuration (near the bottom) is the selector for the "uplink". Unfortunately, it has to be a gig port, but that shouldn't be much of an issue. Attach the cablemodem to "g1" and set all ports to PVE uplink of "g1".