Forum Discussion

Jerry Meyer's avatar
Jerry Meyer
Iron Contributor
Aug 07, 2017
Solved

Migrate Exchange Hybrid Server to other domain

Hi, At a customer we have migrated almost all of the mailboxes from two different domains to One Office365 tenant. Now that we are almost done we are looking into the posibilities of migrating the Hy...
exchange online
hybrid
office 365
  • NunoAriasSilva's avatar
    NunoAriasSilva
    Aug 08, 2017

    Hi Jerry,

     

    You have to Setup a new Installation of Exchange Server on Domain B.

     

    After instalation of the new Exchange Setup, you have to Uninstall Exchange on Domain A and then Run the AD Connect Again to discover the new Exchange and after that changes you Have to setup a new Hybrid Configuration Wizard on Exchange on Domain B.

Jerry Meyer's avatar
Jerry Meyer
Iron Contributor
Aug 08, 2017
Thanks for your response we will start testing this next week in our test lab :) i will keep you posted.
Dominik Hoefling's avatar
Dominik Hoefling
MVP
Aug 08, 2017

Keep in mind that you have to export the MailboxGUID from Exchange Online to your migrated user accounts in domain b in order to offboard users (if required).

And, to avoid downtime, change your MX and Autodiscover record to Office 365, migrate everything to domain b, switch records (if required) back to your new on-premise infrastructure.

Test lab is a good approch :-) Make sure your your identities will be matched correctly and everything will work.

  • Jerry Meyer's avatar
    Jerry Meyer
    Iron Contributor
    Nov 01, 2017

    I have already send you a personal message. I don't know if it allowed but i have worked out this case on my personal blog. I am not sure if it is allowed to share this here. But you can finde the 2 project within the urls bellow.

     

    https://jerrymeyer.nl/2017/10/20/office-365-migrating-azure-ad-connect-new-ad-domain/

     

    https://jerrymeyer.nl/2017/10/23/migrate-exchange-hybrid-server-another-domain/

     

    If you have any question please let me know. Also feedback on the blogposts are very welcome :)

  • Steve Morris's avatar
    Steve Morris
    Copper Contributor
    Oct 31, 2017

    Hi Jerry,

    I am soon to face the same task..

    So we have an on-prem server and all users are remote-mailbox users (according to it) so O365 online users and they are sync'd from domain A using AADSYNC currently.

    We probably also do have a few local security groups, mail contacts and the like in on-prem environment.

    The active directory domain, users have been synchronized using ADMT to domain B in preparation for domain migration (for the users) ..

    So now I have to plan adding an on-prem exchange presence in Domain B also.. again to allow for management of certain attributes that Exchange online doesn't make easy..

    So I'm looking for a fool proof/simple ! way to do this.. and would be keen to hear of any difficulties you had.

    I do not have a test lab.. and so must tread carefully in this task..

    any help/direction would be wonderful.

     

     

     

  • Jerry Meyer's avatar
    Jerry Meyer
    Iron Contributor
    Sep 06, 2017

    Status update,

     

    Currently we have reduced our Exchange farm to a much smaller environment from 15 Exchange server to 2 exchange servers. One Hybrid and One Cashub.

     

    We are now testing a couple of scenarios in our test lab.  Currently we have a succesfull move but it takes a lot of scripting before everything works. For instance the MSexchangerecepientdetails needs to be copied over to the user in the new domain.

     

    I will get into more details when we are further with testing