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Exchange 2010 - can i gracefully change the DC the Exhange server is referring to? RRS feed

  • Question

  • A couple DCs are being decommissioned. The AD team moved the DCs to an "isolation" AD Site, but did not reboot them. We now have several Exchange servers that are still maintaining an active connection to these DCs.

    Since the DCs have been moved out of the AD Site, their names are not present in the DC list in Event 2080. But the Exch server does not reconnect to a different DC.

    I know I can reboot the Exch server, or at least recycle a number of services, and teh Exch server will then connect to a server that is listed as present in the same AD Site.

    Is there a non-impactive way to force the Exch server to select a new DC?

    - if i set a static DC, or add the DC names to the staticexclude list will that force the server to repoint with out further actions?

    - if I wait for the DCs to be decomm'd, what is the expected delay for the Exchange server to reconnect to a different DC?

    Thanks!

    Tom

    Wednesday, July 17, 2019 3:12 PM

Answers

  • So it sounds like the answer to this question is an authoritative:  MAYBE

    If you system has quiet periods where minimal to no activity is taking place, like overnight or weekends, there is a chance that the DC connections may change without a server reboot.

    If you system is highly active where there are no inactive periods, the highest likely hood is that the DFC will NOT change without a server reboot.

    Tom

    • Marked as answer by Tom_Slycke Monday, July 22, 2019 2:40 PM
    Monday, July 22, 2019 2:40 PM

All replies

  • Hi

    If you dcpromo that dc then it will remove from active directory and sites and services and exchange will not use it anymore.

    You cannot just remove a dc by shutting it down. Exchange will change the dc's it connects to periodically. If you want to force exchange to only use certain ones you can do that as well.


    Hope this helps. Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Wednesday, July 17, 2019 4:57 PM
    Owner
  • THe DCs that will be decomm'd have been removed from the local AD Site for a week (placed into an "isolated" AD site). They are no longer displayed on the DC list seen in event 2080. So its been over a week and the Exchange servers have NOT changed the DC they are connected to.

    I understand that a DCPromo will be performed and at that time Exchange should select a different DC.

    I would ideally like to get the Exchange servers redirected to different DCs prior to the DCPromo and am wondering if that can be accomplished without a server reboot, or service recycling.

    Tom

    Wednesday, July 17, 2019 6:42 PM
  • Hi Tom,

    Yes, you can try to set static DC for exchange servers and check if any helps:

    Set-ExchangeServer "ExchangeServerName" -StaticDomainControllers DC1,DC2,DC3 -StaticGlobalCatalogs GC1,GC2,GC3
    If it works, wait for days, and revert back to default setting after old DCs to be decomm'd:
    Set-ExchangeServer "ExchangeServerName" -StaticDomainControllers $Null -StaticGlobalCatalogs $Null


    Best Regards,
    Niko Cheng


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com

    Thursday, July 18, 2019 6:56 AM
    Moderator
  • Nice try Nico, I added the to be removed DC in the StaticExcludedDomainControllers and added a good DC to both the StaticDomainControllers and StaticGlobalCatalogs.  The Exchange servers made no change after close to 2 days.

    I believe a server reboot will need to happen, either the Exchange server, or the DC, to break the established connection therefore requiring a new one to be created.

    I did the same on servers in our non-prod environment and i DID see the DC connections change. My theory is that in non-prod, there is limited traffic / connections. The DC communications at some point were not required and the connection therefore closed.  In production, there are users 24/7 not to mention applications that are attached to mailboxes. The DC connections probably never get to an idle state and cannot close.

    I do appreciate everyone's attention to my question!

    Tom

    Monday, July 22, 2019 3:51 AM
  • So it sounds like the answer to this question is an authoritative:  MAYBE

    If you system has quiet periods where minimal to no activity is taking place, like overnight or weekends, there is a chance that the DC connections may change without a server reboot.

    If you system is highly active where there are no inactive periods, the highest likely hood is that the DFC will NOT change without a server reboot.

    Tom

    • Marked as answer by Tom_Slycke Monday, July 22, 2019 2:40 PM
    Monday, July 22, 2019 2:40 PM
  • So it sounds like the answer to this question is an authoritative:  MAYBE

    If you system has quiet periods where minimal to no activity is taking place, like overnight or weekends, there is a chance that the DC connections may change without a server reboot.

    If you system is highly active where there are no inactive periods, the highest likely hood is that the DFC will NOT change without a server reboot.

    Tom

    I have DCPromo'd servers up and down in the middle of a production day many times. No issues.
    Monday, July 22, 2019 2:48 PM
    Moderator