Multi-domain design help RRS feed

  • Question

  • I have a few questions about Exchange 2010 in a multi-domain forest, particularly since reading that DAGs are restricted to a single domain.

    The company has a moderately sized european presence (~800 users), with small US and Asian offices (<100 users each). Their (brand new, 2008R2) AD forest has a root domain and three child domains based on these geographical areas. Most of the administration is done from the main european HQ. Don't ask me why they have child domains at all - it wasn't my design.

    I had thought first that we would have two Exch2010 servers in europe, and one each in US and Asia. Europe would provide the backup for both US and Asia using DAGs. However we can only do this if all the Exchange servers are in the same domain, and therefore don't conform to the domain divisions they have made.

    My thoughts for possible designs, which I am asking for comments on, are:

    1. Centralise all Exchange services in Europe. This is how they are working today. We have no issues with domains and DAGs, but Asia and US users continue to access their mail over a WAN link.

    2. Install servers in the three regional hub locations, but use the root domain for all of them. This would allow the most flexibility with the DAGs - but are there cons I should be aware of? The root domain seems the best choice for DC placement concerns, but it means opening it up to more administrative access.

    3. Install a pair of servers in each region/domain that just back up each other. This seems like overkill for the smaller regions, but would allow them to place the Exchange servers in the regional domains.

    There doesn't seem to be much out there about Exch2010 in multi-domain forests. I've found a few documents about Exch2007, but with Exchange servers placed in all the domains. I haven't been able to find anything official about what happens when you put all your Exchange servers in one domain only. Is there any problem with having accounts in a different domain to their mailbox server?

    Monday, January 18, 2010 2:51 PM

All replies

  • Dear Carol

    During a AD migration I had the same setup. Users in domain A, exchange in domain B. You can use linked mailbox's ( This way you can centralise the mail servers in europe. Option one. Works very good. Just take a good look at autodiscovery and OWA publicing.

    Martijn B.
    Monday, January 18, 2010 7:03 PM
  • What I don't get though is that is a resource *forest* - I'm not talking about a seperate forest.
    Monday, January 18, 2010 8:30 PM