Just before the Christmas break, I had a case where LMTOOLS reported FFFFFFFF as the Ethernet address, even though ipconfig /all showed a valid Physical address for the network adapater. Because of this, the license server wouldn’t start.

FFFFFFFF (eight F’s) is the broadcast address.

I tried a number of things, like resetting the TCP/IP stack with netsh with no success. I spent quite a bit of time on google, but most of the information was old and no longer applicable.

Eventually I figured out the problem, and was able to reproduce on my machine at home. It was the MAC Bridge Miniport: when I bridged my two network connections, then LMTOOLS thought the MAC address was FFFFFFFF.

To unbridge a network adapter:

1. From the Control Panel, open Network Connections.
2. Right-click your local area connection and click Remove from Bridge.
3. Right-click the Network Bridge and click Disable.