upgrade exchange 2013 cumulative 15 to cumulative 21


i need expert advice to now what i need to do to install exchange 2013 cumulative update 21 from exchange 2013 cu 15 installed.

i am on windows 2012 r2 with  9 server exchange 2013 cu15 and .net framework 4.5.1 (the relaese on registry indicate 378675).

can some one tell me what are the road to upgrade to Cumulative 21?
1- are update active directory schéma is needed?
2-what are the prerequisites
3- are higher .net framework version is needed (actually 4.5.1 on server)

thanks for help
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WadskiIT DirectorCommented:
1. There is no schema change between Exchange 2013 CU10 and CU21 so there will be no AD update required.

2. When you run the setup program it will identify any missing prerequisites.

Because each CU is a full installation of Exchange and includes updates and changes from all previous CU's, you don't need to install any previous CU's or service packs first. Although it definitely requires .net framework 4.7.1 (as per #3)

3. CU21 requires .net framework 4.7.1 so that is a definite and will require a reboot during the installation.  

My advice is to run the setup and let it identify what you need and then note them all down and do these during a scheduled maintenance window then use a 2nd maintenance window to apply the update.  This should mean you have plenty of time and don't inconvenience your users.

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cawasakiAuthor Commented:
hello Wadski

thanks for this, other question, i need to undestand how .net framework work, are the installation of the 4.7.1 delete old 4.5.1 .net framework? i ask because i have scanmail for exchange and i think its support only .net framework 4.5 version.
Hani M .S. Al-habshiContributor as IT ExpertCommented:
Just install CU 21
setup 》run
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MASEE Solution Guide - Technical Dept HeadCommented:
-->1- are update active directory schéma is needed?

-->2-what are the prerequisites
Run the setup would be enough.

-->3- are higher .net framework version is needed (actually 4.5.1 on server)
Install .net 4.6.2
cawasakiAuthor Commented:

what i see here: https://blogs.technet.microsoft.com/exchange/2018/06/19/released-june-2018-quarterly-exchange-updates/

the cu21 of exchange 2013 need .net framework 4.7.1

other question, if i install .net framework 4.7.1, are .net framework 4.5.1 is removed or not? because our mail antivirus work only with 4.5.1 framework version.

WadskiIT DirectorCommented:

It all depends on your version of Scanmail.  If you have version 12.0 then it needs .net framework 4.5.0. If you have 12.5 then it will work with 4.7.1.

Installing 4.7.1 will update 4.5.0 so potentially leave Scanmail unoperational.

This link says Scanmail 12.0 is compatible with CU21 but, as you say, it requires 4.5.0


Do you have support contract for Scanmail? It may be worth speaking with hem if so as it’s ambiguous.
cawasakiAuthor Commented:
HELLO Wadski?

this is exactly my problem, i have scanmail 12.1 its compatible with cu21 but need .net framework 4.5, i have ask Microsoft support and i am waiting the answer to now if when install .net framework 4.7.1 it keep 4.5.1 version or not.

and yes i will ask scanmail support.

WadskiIT DirectorCommented:
When you install 4.7.1 to will replace 4.5.0.

This version of the .NET Framework runs side-by-side with the .NET Framework 3.5 SP1 and its earlier versions. However, it performs an in-place update for the .NET Framework 4, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, and 4.7.
Source: https://support.microsoft.com/en-gb/help/4033342/the-net-framework-4-7-1-offline-installer-for-windows
WadskiIT DirectorCommented:
Found a Microsoft document stating that all versions of .net framework 4.5 and beyond are backwards compatible

cawasakiAuthor Commented:
hello Wadski,

are this mean application need 4.5.x framework will continue work after update to 7.7.1?

WadskiIT DirectorCommented:
Yes.  Which is why it says on the TrendMicro site that 12.0 is compatible with CU21
cawasakiAuthor Commented:

thank for help:

Trend say we need to upgrate to 12.5 first to be supported :).
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