Mac OS X Server 10.1: Setup Assistant May Stop Responding If TCP/IP Is Set Improperly

Symptom

The Setup Assistant stops responding.

Solution

Make sure there is a valid router setting if you are upgrading to Mac OS X Server 10.1 from version 10.0.3 or 10.0.4.

The symptom can occur in these situations:

1. The router address is set to the computer's IP address
2. The router address is not set.
3. The network is configured for DHCP, but there is no DHCP server available.

For example, an invalid setting would be:
IP Address: 192.168.43.154
Subnet Mask: 0.0.0.0
Router: 192.168.43.154

If you want to do something along those lines, use this instead:

IP: 192.168.43.154
Subnet Mask: 0.0.0.0
Router: 127.0.0.1

If the computer is set up with this invalid setting, change the router address in the Network pane of System Preferences for the Built-in Ethernet interface. If you don't do this and the Setup Assistant stops responding on the "Port Planning" page, and you are unable to go forward or backward, then start up the computer into single-user mode, and run the following commands:

fsck -y
mount -uw /
rm -rf /private/var/db/SystemConfiguration exit

This will allow the computer to start up. After this point, when making Network settings, the default router should be set to 127.0.0.1.