Go through all of these and then let us know if you still have the same problem. It will fix certain problems with retaining the WEP/WPA passwords. If you haven't already, run the 10.5.1 update. Is WEP/WPA encryption on? Is the correct password still stored in Leopard OS? Re-enter it on the Mac to be sure. Is MAC Address authentication enabled? If yes, is the correct MAC address (en1 not en0) entered in the table?Īre you connected via ethernet or wi-fi? If Wi-fi, a few things you may want to check, including.

Ensure that it is set to DHCP (nevermind if you already checked this) Is it set to DHCP? If it's set on a static IP there may be an IP collision. I see that you said you tried different computers on different cables, but I don't see you stating you tried the same computer with a different cable. Try a different ethernet cable on the computer that isn't connecting. This will force the DHCP assignments to clear and renew hard for every device. Without having seen your actual settings on your Mac and router, there are a few things I'd suggest checking.

Mac ethernet self assigned