How can I block a computer (not on Wireless) from my linksys router by IP or MAC Address? I am using a linksys WAG200G.
AFAIK, Linksys routers do not support this for the wired interfaces. They assume that if you have physical access than the node is supposed to be able to connect. You might have some luck with one of the open source replacement firmwares (tomato, openwrt, dd-wrt, etc.) and firewalling the host via iptables.