Just renewed my Comcast Cable internet (I've been on DSL). I have an Arris Model TM502G modem connected to a 3Com 3C16700 8 way router with a CAT 5 cable. The router then has 2 CAT 5s running to a home-made desktop and a Del Inspiron 8600 laptop. Both run Windows XP, the laptop has Service Pack 3, the Desktop is still on service Pack 2 (I'll D/L 3 tomorrow).
No matter what I do I can only get the net to work on one machine at a time. I can get either machine to work with a CAT 5 directly from the Modem to the machine, or one at a time with everything connected. I am certain all the cables and ethernet cards are working in each machine. Card drivers are also fine as far as I can tell.
I have tried to cycle all the hardware in order several times, with or without batteries in it. I have tried ipconfig /release and /renew on the laptop several times. It always tells me it can't communicate with the DHCP server. I've tried turning off my Firewall. I have not tried to clone or force IPs at all, but I know both computers are properly set to "Obtain an IP address automatically" in the TCP/IP options for XP's network connections.
I am out of ideas and Comcast says they can't give me any advice b/c they didn't sell me the router...any advise tech gods?