[Samba] Acronyms: what is PDC and BDC?

Marc Muehlfeld samba at marc-muehlfeld.de
Tue Mar 4 04:41:41 MST 2014

Hello Louis,

Am 04.03.2014 10:14, schrieb L.P.H. van Belle:

> Forget PDC of BDC , ( not if you using samba 3, there it exists)
> samba 3, then we talk in PDC/BDC style ( think in master - slave )
> samba 4, the we talk in AD-DC style ( think multi master ) ( and slave maybe bit as in RO ADDC )

That's not correct!

Version 4 of Samba can be installed as an AD DC, but also as a NT4-style 
PDC like it was in all previous versions.

3x can only be a NT4-style [P|B]DC. 4x can be additionally provisioned 
as AD DC. And of course 3+4 can be a member in both kind of domains.

 > and this is why we always must tell which samba we are working
 > with..  ;-)

Users should always post their version _and_ if they are using it as AD 
DC or an NT4-style PDC.

>> Yes, good. First; primary, hence PDC?  No, still AD-DC
>> AD doesn't have a PDC. half correct it has a PDC-emulator ;-)
> as the wiki says..
> The "PDC emulator" master acts in place of the "Primary Domain Controller"
> => !! if there are Windows NT 4.0 domain controllers (BDCs) remaining within the domain  !! <=
> correct me if i'm wrong..

That's not all it does. Here is a better explanation:

You can't drop the PDC emulator role or disable it, when all NT4 BDCs 
are removed! If the DC with this role is down, then different things 
won't work in an AD. Here's a list about its functions:


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