I just got a new workstation today. It has two network cards, just like my previous AMD-based workstation, and I did not have this trouble with it (same configuration, as far as I can tell...I must be missing something).

I use one of the NICs to connect to the cable modem. I use the other to connect to my network DVD player. My network DVD player cannot provide an IP address. So, I have to enter a local IP address for that NIC. When I do this, the Internet does not work anymore (although that NIC does not seem to report any trouble). If I have the NIC for the network DVD player set to obtain automatically, the Internet does work, but then that NIC reports limited or no connectivity, and the network DVD player does not work. Anyone know why the Internet does not work once I set the secondary NIC to a local IP? The NIC used for the Internet is set to obtain automatically. Thanks.

Try setting the second nic to bridge mode.