On the Windows NT 4.0 BDC, check to see if the Netlogon service is started. If NOT, see if the System event log contains:

Event ID: 3210
Source: Netlogon
Description: Failed to authenticate with <ComputerName>, a Windows NT domain controller for domain <DomainName>. Data word: c0000022

NOTE: The event log on the PDC emulator may not contain an corresponding event, but replication is NOT occurring between the BDC and the PDC emulator.

To adjust this behavior:

1. Control Panel / Administrative Tools / Local Security Policy.

2. Double-click Local Policies.

3. Expand Security Options.

4. Double-click Additional restrictions for anonymous connections and select No access without explicit anonymous permissions.

5. Restart the member computer or domain controller to make the change effective.