Hey guys,I am deploying a network for a business, here is the planThere are 3 sites A,B,Csite A: 43 clients, all the servers are in a rack in the basementsite B: 20 clientssite C: 20 clientsi want AD fcourse but i'm wondering if it is possible to use site A domain controller as PDC, and put a BDC on site B,Cso if site A is down users can still log-on to domain, and if either site B or C is down, then site A can still work because of dc on B,C (all trough vpn)network drawing includedIf you see any improvements i would like to know, (failover is important)Money is not really an issue, but not over the tophttp://img143.imageshack.us/my.php?image=gif1gq4.gif

Dear customer: Since your issue is about AD topology design, which is out of our support boundary. Please post your issue into the following forum, maybe you can get much help in there. TechNet Forums Windows Server 2008 http://forums.microsoft.com/TechNet/default.aspx?ForumGroupID=161&SiteID=17 Also, I would like to provide some basic information for your reference. In Windows server 2000 or 2003 and later, there is no PDC and BDC concept. Active Directory service replication is multi-master; an update can be made to any domain controller in it, and the change will be propagated to other domain controllers. So you can install a DC in at each AD site for redundancy. For more information about Active Directory design, you can refer to the following documents: Best Practice Active Directory Design for Exchange 2000 http://www.microsoft.com/downloads/details.aspx?familyid=f53662b9-4e69-40ce-aa19-7b0c48710403&displaylang=en Active Directory Architecture http://technet.microsoft.com/en-us/library/bb727030.aspx Active Directory All Chapters Download http://www.microsoft.com/downloads/details.aspx?FamilyID=9a4c7ac3-185e-4644-9e98-4876b2a477e7&DisplayLang=en Hope it helps. Rock Wang - MSFT