Forum Discussion
Two different domains in one Office 365 tenant
Hi,
There can be only one Azure AD Connect instance for a single Azure tenant. This means, you have to use one AAD Connect instance for both companies, if you want to go single tenant.
Azure AD Connect supports connecting multiple forests to a single Azure AD tenant. A server that runs Azure AD Connect does not have to be joined to any domain locally, however, it must be able to access domain controllers in both forests.
In some cases, you can choose to place the Azure AD Connect server in a (DMZ), especially if you do not have a direct network connection to all forests that you would like to include in the synchronization.
If you need more information, you probable should tell what is your goal and how both companies must work together.
In the case of having multiple Azure AD tenants, AAD sync, separate AD Forests with trusts:
Can a user in Company A manage an Exchange resource in Company B?
You can grant delegated access to another company so they can manage your O365 tenant using their credential.
https://support.office.com/en-us/article/partners-offer-delegated-administration-26530dc0-ebba-415b-86b1-b55bc06b073e
- That functionality is only available to verified/certified Microsoft Partners; it is not designed for two companies to share administration.
Is there a solution for Company A with on premise Exchange to manage Company B's resource calendar on O365?
