Forum Discussion
Multiple forests, single Azure AD tenant
Hi all,
Here is current setup
One O365 tenant with
One AD forest name domainA.com
One AD forest name DOmainB.com
There is full trust between both forest
Both Forest have their own Exchange 2013/2016 server
Azure AD Connect is installed on DomainA.com and both forest are synced to same O365 tenant
Exchange hybrid ran successfully from both forest and Azure AD connect successfully sync AD accounts from both forest.
Question is:
Can we use same migration endpoint for both forest or do we need separate migration endpoint for each forest?
Problem is:
Migrating mailbox from DomainB.com fails, so does incoming mailflow to DomainB.com. Currently mx record for domainB.com is pointing to Exchange Online. DomainB.com have successfully been added to the tenant.
Tried to find documentation regarding this setup, but so far haven't found any.
Need advice.
thanks!
:)
4 Replies
You need a separate namespace as detailed here: https://technet.microsoft.com/en-us/library/jj873754(v=exchg.150).aspx
- Namespace planning
Each forest in which you install Exchange requires its own unique externally-discoverable namespace. You'll specify a forest's unique namespace in the Hybrid Configuration wizard when you run it in each forest.
Thanks Vasil,
regarding namespace, it should be ok to point MX record to Exchange online?
Mail(OWA) and Autodiscover should be pointed to on-premise.
During hybrid config wizard I already did specify separate namespace (mail.domaina.com and mail.domainb.com)
Still I don't understand why emails are not delivered. I have already changed both domains to internal relay in O365. Maybe I need to create separate connector for both on-premise to communicate over. Will need to test it tomorrow when I'm back at work
Yes you need to run Hybrid Wizard it will setup the connectors for you !
- Namespace planning
