The best tool to figure out how your network looks like in a MS Domain is nmblookup. Following commands should tell you what you need to know:

nmblookup -R -U 192.168.1.55 WORKGROUP#1C
where 192.168.1.55 is the IP address of your WINS server and WORKGROUP is the domainname. This results in a list of the domain controllers available on your network. You could also request the Domain Master Browser by doing:
nmblookup -R -U 192.168.1.55 WORKGROUP#1B
This should result is the IP address of the PDC, since according to the rules in Microsoft Networking, the PDC must be the Domain Master Browser.

To collect all functions of a single host use:

nmblookup -R -A 192.168.1.66
or if you want to do it based on NETBIOS name use:
nmblookup -R -A 192.168.1.55 -n MyPDC