Patches downloading from Microsoft.com (possibly other URL as well) are failing with 401 Unauthorized or 403 Forbidden

Products

• IT Management Suite
• Client Management Suite
• Patch Management Solution

Issue/Introduction

When trying to stage patches we are getting 40 Unauthorized and 403 Forbidden errors.  Most of the updates are downloaded for other bulletins, but specific bulletins are not able to download. 

Environment

ITMS 8.x

Patch Management 8.x

A Proxy is configured in the environment

Cause

Errors:

The remote server returned an error: (401) Unauthorized
The remote server returned an error: (403) Forbidden

Resolution

The remote server in this case was the Proxy.  401 Unauthorized error was returned when the URL was not whitelisted, in this case the new URL was builds.dotnet.microsoft.com. 

The 403 Forbidden error was when a file with extension .exe was not permitted through the Proxy for that URL.

The resolution was to whitelist on the Proxy all of the needed download URLS.