It is done via NetBIOS names. The domain name 1c group
name contains the tcp/ip address of the PDC and and all other
BDCs up to 25 in the list.

"ZIDAC" <ZIDAC@discussions.microsoft.com> wrote in message news:
> Hello, this is my question:
>
> In Windows 2003 Server you can install de primary DC and the secundary DC,
> when client is configured is set DNS1 = DC1 and DNS2 = DC2, when DC1 is
> wrong, the client logon to DC2 (it is transparent for clients)
>
> Who is this process in NT ?
> Who discover the client the BDC to logon when PDC is wrong in NT scenario?
>