Office 365, Hybrid, On-Prem CU Upgrade.Exchange 2016.

[Robert Bollinger]

Hey Guys,

This evening we are supposed to upgrade our on-prem exchange servers to CU 8. They are currently running CU1 (so pretty old). Due to the .net requirements of the various Exchange CUs I am going to apply CU4 then install .net 4.7.2 then Apply CU8. This is for Exchange 2016.

The Schema has already been updated, however before I start the process, is there any thing I should be aware of before upgrading the exchange servers specifically as it relates to office 365? I have performed dozens of CU installs on Exchange Servers, but when those servers had office 365 hybrid configured.

Our Autodiscover records are pointed to the cloud. We have all of our mailboxes in the cloud. however we do have dynamic distro groups.

Thanks,

Robert

[#2 · Accepted solution]

Hi Robert,

Since you do not have nothing pointing to Exchange, you can do the upgrade without any downtime.

See the upgrade paths in the below requirements.

If you're upgrading to Exchange 2016 CU4 from Exchange 2016 RTM, CU1, or CU2, is recommended that you install Exchange 2016 CU4 before .NET Framework 4.6.2 or .NET Framework 4.6.1 and its related post-release fixes.

After this install Exchange 2016 CU8 and then .NET Framework 4.7.1

Please see the requirements https://technet.microsoft.com/library/bb691354(v=exchg.160).aspx and here also https://technet.microsoft.com/library/aa996719(v=exchg.160).aspx.

[#3]

Thanks Nino. I meant to put 4.6.2 in my original post. I am actually going to upgrade to that version of .net and not 4.7.1. (The 4.7 version will come later).

Thanks,

Robert

[#4]

Ok Robert. Keep in mind that you now also have CU9 available to install.

[#5]

Hello@Nuno Silva    

we have two on-prem exchange server and 2 Hybris servers in Co-existance .All of 4 servers running exchange 2016. Although we have migrated all the mailboxes to o365. But Mailfow is still though on-prem to O365, as MX records are not switched yet. 

We are planning to upgrate exchange 2016 CU10 to exchnage CU12. So is there any process for Upgrade . Like Ist Hybrid servers  and then other exchange on prem servers. 

[#6]

Hi @Avinash1991,

You can now change the external mailflow to Office 365 change the MX if you have migrated all mailboxes is advised. Regarding the CU's you can install first on Hybrid and then the others. 

[#7]

Hello@Nuno Silva 

In regards to CU installation, is this standard process to ist install on Hybrid server. Because some articles are suggesting we can do it vica-versa, on On-prem and followed by hybrid.

Can you please help me with any microsoft article . thanks

[#8]

Hi @Avinash1991,

Always the front-end servers first. 

You can read more here https://docs.microsoft.com/en-us/exchange/plan-and-deploy/install-cumulative-updates?view=exchserver...

[#9]

Hello@Nuno Silva , we have switched the MX recored to O365 . But weired thing happening. Majority of e-mails are going throgh O365 as per MX. But Some e-mails are still getting delivered throught the old e-mail gateway. 

Any suggestion on this.

[#10]

Hi @Avinash1991,

How much time has passed the changes of MX record and what was the TTL of that record ? 

[#11]

Hi@Nuno Silva its been 3 days sice we have updated the MX. And We have set the  TTL value to 5 min.

Also post switching the records to o365 does mails route through the hybrid servers.

[#12]

Hi @Avinash1991,

Every email's are routed through hybrid servers are from the same domains ?  You only have one MX ? The source domains maybe have a direct route to your previous record.