Make sure the server network board is installed or seated correctly and is initializing when the server is started.

Make sure that the server network board is configured correctly.

Check the network board configurations of the boards in the server and the settings shown on the server and make sure that the settings match.

Make sure that all server and workstation network boards are seated properly and that cabling and connections are attached securely.

Make sure that the terminators on cables have the right ohm rating and are installed correctly. The IBM PC Cluster sends a broadcast message during initialization, then stops processing if the network is not cabled or terminated properly.

Check the network boards in all workstations for correct node address settings.