In Windows 2000, when you type:

nltest /dsgetdc:<NetBIOS_Domain_Name> /GC

you receive:

DsGetDcName failed: Status = 1355 0x54b ERROR_NO_SUCH_DOMAIN

Why? The tool is broken.

You can use the NetBIOS name to query the PDC and the KDC (Kerberos Key Distribution Center), but until it is fixed, use the DNS Domain Name to query the GC.