>So, Now, I have a new Red-hat Linux setup, nothing fancy, just basic configuration. I set the ethernet to STATIC IP 100.100.100.30 (ex: something not already in use), gateway, primary/secondary dns. I am not getting any connection to the router... can't even ping.
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>However, If I connect the network card directly to the cable modem, and set the IP information with the main STATIC IP, Gateway and DNS info, all goes through.

Concurring on the other comment about your IP address range - I personally use 192.168.0.x internally. Using any IP range not specified for internal use is asking for trouble down the road.

As for your problem, are you using Red Hat 7.1 or 7.2 and if so, did you allow the installer to put up any firewalls? If so, that may be the root of your problem - the default iptables setup tends to be overly restrictive, and will play havoc with that machine's Internet access, Samba and other aspects of your network. Besides, an internal machine shouldn't need a firewall - only the router (or machine directly connected to the Internet and used as the router) should be firewalled, unless you're setting up a complex corporate structure.