Existing Office 365 hosted Exchange - Adding on Premise AD with Azure

Hey All,

need to know what would happen to an online environment  that is established and working (Hosted Exchange) and then adding a local on premise Server 2012 AD DC with Azure dirsync and single signon?  
For example, normally we setup the O365 environment and then setup the on premise AD server and installed Azure.  Adding all users locally and having Dirsync to populate the online environment.  
When looking at the O365 admin portal, the users sync'd with dirsync show "synchronize with AD" and not "cloud."  Thus all changes to users, etc come from AD.

I have a new install where I'm going to need to get the online services up first and entering all users and getting email flow working before the local on premise AD server will be setup.

Cannot seem to find a solution or what will happen with the users when they exist in both places and then setup Azure for dirsync, etc.

Any ideas how this would be handled?

Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Vasil Michev (MVP)Commented:
If you are looking to "match" the on-prem users against the existing users in O365, you have two options:

1) soft-match, based on the primarySMTPadderss attribute: http://support.microsoft.com/kb/2641663
2) hard match, based on the objectGUID: http://blogs.technet.com/b/praveenkumar/archive/2014/04/12/how-to-do-hard-match-in-dirsync.aspx

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
RFloyd30Author Commented:
Thank you. Did some more indepth searching myself and found these as well but ice to have a confirmation that it should work
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Office 365

From novice to tech pro — start learning today.