In Windows NT, they had the concept of a Primary Domain Controller and a Backup Domain Controller. In NT on the PDC was writable and the BDC's where just a copy of the information on the PDC. This was so the the BDC could take some of the authentication load and also had a backup of the Domain User/Groups, etc... should anything happen to the PDC.
In Windows 2000+ this concept was changed so that all domain controllers where writable and replicated changes amongst each other. (There is a term for this which escapes me)
Hope thats what you was asking.
Wayne Murphy
Firewall.cx Team Member
www.firewall.cx
Now working for a Security Company called Sec-1 Ltd in the UK, for any
Penetration Testing work visit
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or PM me for details.
