NT BDC problem

I have an NT4 domain. Any 2000 or XP computer can join the domain without a problem.

I am trying to create a BDC, but it always says “The domain controller for this domain cannot be found.”

I’ve tried this with many computers with different network cards. If I set up any of these computers as an NT member server, I can browse the net, and ping all everything on the network, so I know I have the correct net drivers.

WINS appears to be configured correctly.
What did I miss?