This happens if you are using only the PCI Ethernet card and not the built-in Ethernet port. This issue affects: 
-  Mac OS X Server 10.3 to 10.3.2
 -  Xserve
 
There are two ways to avoid the issue. One is to use the built-in Ethernet port. The second is to configure the built-in Ethernet port, but not use it. Follow these steps: 
 
-  Enable the built-in Ethernet port.
 -  Configure it for a static IP address. 
 -  Save the changes. 
 -  Don't connect a cable to the port. 
 
 
This document will be updated when more information is available.