Migrate OnPrem Domain with exchange online

Question

Hi,

we have 2 OnPremise Domains, on is Exchange Hybrid. For Example:

old.dom (With Exchange 2019 Hybrid and Azure Sync with mS-DS-ConsistencyGuid)

and

new.dom, azure Sync Server ist here and many Servers.

We want to migrate to Exchange Online an move OnPremise AD to new.dom.

I dont found Information about this Szenario. Could anyone help me here?

Where can i find information, what is the best way to do this?

Kindly Regards,

Answer 1

Hi @Jonny-Me

If you have 2 separated On-Premises AD Forests which you want to migrate in one Exchange Online (Microsoft 365 Tenant), you need to have a trust between the 2 OnPrem AD Forests and synchronize the identities for both AD Forests with one single Azure AD Connect.
Then you need to configure the Exchange Hybrid on both AD Forests with the Hybrid Configuration wizard.

See information in this Microsoft Learn documentation: https://learn.microsoft.com/en-us/exchange/hybrid-deployment/hybrid-with-multiple-forests

Hope this helps - best regards, Doudi

Answer 2

Hi Adrian,

thanks for your Quick reply, in between I found additional Information, too.

https://learn.microsoft.com/en-us/answers/questions/579138/cross-forest-ad-migration-and-aadconnect

https://learn.microsoft.com/en-us/answers/questions/1095/azure-ad-connect-source-anchor-in-cross-forest-mig

With your Link an these Links I should be able to solve this.