Exchange 2013 with different CU levels.

Hello, I have a 5 server exchange with 3 of them on a DAG and 2 of them hosting DB's for different elected offices that have to be seperate from the DAG. They are all currently on CU15, I need to update all of them to CU18. Can the be done over the course of a few days or do I have to do them all at once?

They are all exchange 2013 on WS2012 R2
Brandon MillerSystems AdministratorAsked:
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You want to have all members in DAG running the same version, it's what recommended.
Make sure to read Release Notes, as it contains a new requirement such as .NET 4.7.1

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viktor grantExchange ServersCommented:
HI Brandon,

It is recommended to have the same version with same CU in DAG in order to work correctly.

Brandon MillerSystems AdministratorAuthor Commented:
I figured I would need to do them at the same time. I was more worried about the .NET update affecting the none DAG members. Sounds like I will be doing all them at the same time. Thanks for the help.
Brandon MillerSystems AdministratorAuthor Commented:
Thank you.
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