Remote Access on W2K Professional

I am experimenting with dial-up RAS on W2K Pro, and find that I cannot logon to a domain. I can logon as a local user and browse workgroup members, but not the domain.

The event log states:

The user DOMAIN\REMOTEGUY failed an authentication attempt due to the following reason: The current configuration only supports local user accounts.

How do I enable domain user logons from W2k Pro RAS?