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Hi, we're currently in the process of migrating to first a Hybrid Exchange 2016 to O365 tenant, and eventually making the cutover and decommissioning our on prem server. I setup AD Connect and changed UPN's, and users and group look good in the tenant. Setup conditional access for further security. Now I need to install the Hybrid connector wizard, but in doing research i'm a bit nervous.
I'm currently running Exchange 2016 CU15 (December 2019 update), and current is CU18 (Sept 2020).
MSFT always recommends the latest version in order to obtain a supported environment. It's very tough for us to take the single server offline and upgrade it, since it is downtime that they really don't want. That said, if it's a MUST, I guess we can.
In reading about the current connector (they don't really have versions when I download them) it says you have to be running CU18 (September 2020) since major updates were done to the connector. Please see these 2 articles I found: 1. https://techcommunity.microsoft.com/t5/exchange-team-blog/march-2020-significant-update-to-hybrid-configuration-wizard/ba-p/1238753 2. https://support.microsoft.com/en-us/help/4583653/september-2020-update-to-exchange-hybrid-configuration-wizard
My question is - If I run the hybrid connector wizard from my current on prem Hybrid link, or from my O365 Hybrid link will it download the proper version that I need for my setup and work, OR - will it default to the latest downloadable version, and will I then run into issues using it since i'm at an older CU update?
Just wondering if someone from MSFT with knowledge on this can please reply. thanks!
A couple of things:
You won't be able to remove this server as long as you are running AADConnect to be supported. You have to have at least one on-prem server for mgmt.
https://video2.skills-academy.com/en-us/exchange/decommission-on-premises-exchange#scenario-two
That leads to your specific questions :)
Don't take any shortcuts or attempt to run an older unsupported version with the HCW, there really is no good reason to do that and you need to be in a supported version so you can take advantage of the latest HCW fixes.
Additionally, if you are at CU15, then you are missing critical Exchange security updates that are baked into CU18.
https://support.microsoft.com/en-us/help/4571788/cumulative-update-18-for-exchange-server-2016
The latest HCW version will automatically download, the older versions that supported your version of Exchange will not - they are gone :)
So, bottom line:
Upgrade Exchange to the latest CU
Download the latest HCW and configure your hybrid config
Future-proof!
Trust me. You are going to have this server around for awhile
P.S. Alternatively, if you are hesitant to upgrade the existing server, you can always bring up a new one at the latest CU and use just that server as your hybrid endpoint. That would work as well..
Great answer, thanks again!