WSUS: Setup WSUS 2012 R2 stalls when SSL / 443 is inspected by Web Filter

WSUS: Setup WSUS 2012 R2 stalls when SSL / 443 are inspected by Web Filter

While you finish WSUS Server installation you get an error

Error:

Windows Server Update Services Configuration Wizard

Synchronization Error Details

The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.

Solution:

Make a new Firewall Policy depending on your Firewall/IPS/Web Filter which opens Port 443 to *.Microsoft.com and does NOT Inspect/Break/Deep Inspect SSL traffic.

How to check if someone breaks SSL from and Endpoint you are on

On the machine you install WSUS open https://www.microsoft.com and check the Certificate.

If issued by "Shows a local domain" or a another Certificate than Issued to then the company

breaks the SSL traffic on Servers where install WSUS.

Ask the security engineer to make a new firewall rule from that server IP to *.microsoft.com Port 443

and DON'T break SSL in that rule.