PENDING Configuring Office LTSC Updates via SCCM (SUP) in an Isolated WSUS Environment

[zahrim]

The current architecture is as follows:

• Need update Microsoft Office 2021 LTSC
• SCCM (version 2409) with the SUP role, no direct internet access. It receives updates from WSUS1.
• WSUS1 is also isolated from the internet and synchronizes with WSUS2 (like upstream proxy), which downloads updates from the internet.

When enabling updates for Microsoft 365 Apps / Office 2019 / Office LTSC, SCCM attempts to download updates directly from the internet, even though the updates are already downloaded on WSUS1 and ready for distribution.
Attempting to use "Third-Party Software Updates" to distribute Office LTSC updates from WSUS1 results in Error 193.
Questions:

1. How can I properly configure Microsoft Office 2021 LTSC updates in this setup so that the SUP retrieves updates only via SCCM → WSUS1, without attempting direct internet access?
2. Is "Third-Party Software Updates" the correct approach for this scenario? If yes, how should it be configured to avoid errors?

Additional Details:
Has anyone tested a similar configuration successfully?
Are there alternative methods (e.g., offline deployment via SCCM) that could be used instead?
Any advice or documentation references would be greatly appreciated!

 

[Ichiro]

The current architecture is as follows:

• Need update Microsoft Office 2021 LTSC
• SCCM (version 2409) with the SUP role, no direct internet access. It receives updates from WSUS1.
• WSUS1 is also isolated from the internet and synchronizes with WSUS2 (like upstream proxy), which downloads updates from the internet.

When enabling updates for Microsoft 365 Apps / Office 2019 / Office LTSC, SCCM attempts to download updates directly from the internet, even though the updates are already downloaded on WSUS1 and ready for distribution.
Attempting to use "Third-Party Software Updates" to distribute Office LTSC updates from WSUS1 results in Error 193.
Questions:

1. How can I properly configure Microsoft Office 2021 LTSC updates in this setup so that the SUP retrieves updates only via SCCM → WSUS1, without attempting direct internet access?
2. Is "Third-Party Software Updates" the correct approach for this scenario? If yes, how should it be configured to avoid errors?

Additional Details:
Has anyone tested a similar configuration successfully?
Are there alternative methods (e.g., offline deployment via SCCM) that could be used instead?
Any advice or documentation references would be greatly appreciated!

Hi Zahrim! I am basically having this same predicament and was wondering where you went from here? My upstream WSUS has basically downloaded all of this but none of those updates from that product are in my SCCM for some reason, and when I sync, i see in the logs it is failing to reach 'go.microsoft.com'.

 

[zahrim]

Hi Zahrim! I am basically having this same predicament and was wondering where you went from here? My upstream WSUS has basically downloaded all of this but none of those updates from that product are in my SCCM for some reason, and when I sync, i see in the logs it is failing to reach 'go.microsoft.com'.

Hello! We couldn't find a solution. Microsoft writes that you can only download updates from the Internet. Tried through PowerShell, doesn't work.