Originally posted by: Dahak
first check to make sure the router has dhcp turned on, if so then check the next
1) for OS X(10) got Apple -> System Preferences -> Network -> Select Built In Ethernet and make sure that TCP/IP is set to Using DHCP
OS 9 dont have it right handy, but in the control panels, TCP/IP make sure that it is set to DHCP in there as well