Which server to choose in Hybrid Configuration Wizard when adding new Exchange2016 server into existing Hybrid Environment with Exchange 2010?

Question

Current environment has an on premises Exchange 2010 server configured in Hybrid Mode with Office365 with all mailboxes hosted within Office365.

We just installed an Exchange 2016 server into the environment in order to move towards it within the next few months and decommission the Exchange 2010 server.

I ran into some issues where the setup for Exchange 2016 wouldn't proceed once it detected the existing Hybrid configuration. Using the Built-in Hybrid Configuration Wizard which exists within the Exchange 2016 installer.

Microsoft had me go the route of installing it via powershell using this article:

• https://social.technet.microsoft.com/wiki/contents/articles/37405.how-to-install-exchange-2016-using-powershell.aspx

However because that article doesn't take into consideration an existing Hybrid Environment, there were additional steps. Mainly needing to export/import the tenant configuration file to run the setup:

https://support.microsoft.com/en-us/help/3121439/error-when-you-run-setup-prepareschema-to-prepare-the-schema-for-an-ex

1. Setup finally completed successfully
2. I manually configured proper certificates and virtual directory urls to point to Office365.

Everything on the new server appears to be functioning correctly. However I don’t believe the new Exchange2016 server has all the proper send/receive connectors to get into Office365. On the old exchange server, it contains specific IP addresses within the send/receive connectors to communicate with Office365.

I was trying to run the Hybrid Configuration Wizard within the new Exchange2016 server in case there was anything the setup missed.

However, please look at the screenshot.

1. Should I choose both options?
2. Or should I only choose the new server?
3. The old server is still in production and will remain for a few weeks, and it’s already configured for Office365…. So I am not sure if I should be choosing it again?

I don’t know, if I don’t choose the old server….. will it remove the old server from the hybrid configuration? How do I move forward?

EXCH2010 is the current server already configured with Office365.

Hybrid is the new server, it’s pretty much configured but just missing some of the inbound/outbound office365 connection settings.

All I am trying to do is make sure the new server is configured correctly for hybrid, while leaving the old server intact.

Answer 1

The old hybrid server is still selected, you have to select the new hybrid server and deselect the old hybrid server here. Two important steps in the Hybrid Configuration Wizard is the creation of the Send Connector and Receive Connector used with Exchange Online. The servers you select here will be used for SMTP communication between both environments. I suggest you select Exchange 2016 as the hybrid server. Since you want to use your hybrid server just for management purposes, Exchange 2016 will give you a nice management interface. And On January 14, 2020, Exchange Server 2010 will reach end of support.

Answer 2

You definitely want to have your 2016 server be the hybrid server going forward, for several reasons. Changing hybrid servers does not disconnect all the other Exchange servers in the same Exchange organization from Office 365, it just changes how the mail flows and how the other information is updated.

Currently, messages between on-prem and Exchange online all flow through your 2010 server. If you had a whole bunch of 2010 servers, then all of them would have to send messages to the hybrid server to be sent up to the cloud, and vice-versa. The routing between the on-prem servers is automatic when they are in the same Exchange Organization.

So if the new 2016 server is in the same Exchange Org as the 2010 server, then no matter which is the hybrid server they should both be able to route to Exchange Online.

Note that your Office 365 plan includes support, so instead of trying to work it all out yourself with SE help, you can just open a case in the admin portal saying you want assistance with changing your hybrid server. You've already paid for the support, you might as well use it.