Jul 26 2020
09:54 PM
- last edited on
Feb 10 2023
04:31 PM
by
TechCommunityAP
Jul 26 2020
09:54 PM
- last edited on
Feb 10 2023
04:31 PM
by
TechCommunityAP
Greetings.
We have two company's (each with their own forest and single domain) that have operated in a trusted ADDS forest configuration. Each forest contains their own respective mail system. One has on-premise Exchange 2013. The other ADDS forest has O365 and uses Azure AD Connect to sync on-premise ADDS users to o365. These mail systems are utilizing Galsync (enow) to support cross forest GAL's.
We are not (yet) using o365 SharePoint, one drive, or other 0365 services other than email. *We will later in the new named entity.
We are now going to merge these two environments (ADDS forest(s) / domain(s)) into a new named ADDS entity (forest and domain) - and new o365 tenant. This new named entity will utilize many of the o365 offerings.
I have migrated/merged trusted forests, and Exchange on-premise 2010/2013 systems together via ADMT and mailbox moves. This looks to be a bit more challenging.
Has anyone performed a similar migration/merge? Would they be willing to share how they did it?
Any insight, links, or thoughts are very much appreciated.
I found something similar in a forum on reddit -https://www.reddit.com/r/Office365/comments/93f4oq/cross_forest_office_365_migration/
Thanks in advance,
Jul 27 2020 12:36 AM
Hey @Floyds_on_Greenwood ,
Couple of questions here, Are you planning to keep on-premises exchange post merger ? or is it just going to be office 365 with objects being synchronized from on-premises active directory with AADConnect ? are there plans to consolidate on-premises active directory as well ( like AD user migration from one on-premises active directory to another) ? AADconnect does support synchronizing objects from two different on-premises active directories via single AADconnect server ( There are a few prerequisites though).
Jul 27 2020 09:28 AM
Jul 27 2020 11:18 AM
Hey @Floyds_on_Greenwood ,
Here is an article which explains about adding an additional directory in AADConnect : https://www.mustbegeek.com/setup-azure-ad-connect-to-synchronize-multiple-active-directory-forests/
There are other links in the article talking about prerequisites like Trust between the forests, conditional forwarder etc. You can achieve the configuration without trust as well, the article is a bit old (and has a few ads now agggh) but still works well. Will drop response to your other query in some time a bit occupied right now.
Thanks
Jul 29 2020 09:20 PM
Appreciate your help very much @harveer singh
Jul 30 2020 03:50 PM
Hey @Floyds_on_Greenwood ,
Sorry to keep you waiting, a few more question for you, are you planning to migrate both the ADs ( one with exchange 2013 and the other with Dirsync) to a new forest all together, or are you simply merging the two forests ? Going with merge would certainly remove quite some complexity and would make the plan a bit simpler. Also is it a compliance requirement to move away from the office 365 tenant you already have? If you can stick to the same tenant and simply add the new domain in the same tenant , it would again ease your work and you wont have to perform a tenant to tenant mailbox migration ( I am assuming you have mailboxes in office 365 for the other forest).
Jul 31 2020 10:14 PM
Hello @harveer singh
I don't believe we could rename the existing tenant - correct?
We will migrate both into a new forest - yes. It will be a new company name. We need a new tenant name to follow the name for the new company.
companya.local
companyb.local
into mynewcompany.org
Aug 01 2020 11:45 PM