I have a newly installed Fedora Core 3 machine with onboard nVidia ethernet. I assembled and tested the machine in my living room with a direct connection to my router. Everything was working fine in this condition. I then moved the machine into my basement and attempted to connect via a switch that is connected to the router. I am unable to connect to my local network or the internet.

ifconfig shows the machine has received an IP address. The router shows that it has assigned an address to the machine. A laptop connected to the same port on the switch connects without issue. Any thoughts as to what is preventing my FC3 machine from connecting?

Can you ping any of the machines or can they ping that machine? If you have an IP address you should be able to ping (connect to) your LAN. As for the internet, you could try adding a nameserver entry to /etc/resolv.conf, for example:
nameserver 192.168.1.1
using the IP to your router. But if you can't ping the LAN you have to sort that out first.

The machine is working now. I don't know why. At the time, I was unable to ping successfully. Now, ping works fine. Nothing looks any different in terms of the ifconfig info. Also, the router log shows the same info. I guess for now I will just be happy that it is working unless it stops again.

Thanks for the suggestion.