Hi @caterina ,
First and foremost, Microsoft has effectively discontinued Windows Integrated Authentication (WIA) in favor of more modern and secure environments. As such, we strongly advise taking this opportunity to simply move away from it.
Our recommended environment is:
No authentication required to view/download packages
the only exception to this is packages containing things like trade secrets.
that should not be the default, as "when everything is secret nothing is"
API Key required to publish packages
minimal permissions (i.e. no overwrite)
limit to feeds when appropriate, so you don't have too many keys
consider rotating annually
That said, WIA is still supported in the Integrated Web Server and unsupported feeds (like npm) are automatically excluded from WIA when Kestrel is used (i.e. when you are NOT doing port sharing, and binding to a port). You can also explicitly exclude NuGet feeds.
However, it's not possible to do "authentication by port", like what was possible by creating two sites in IIS.
Hope that helps,
Steve