Alias for Portal for ArcGIS 10.6.1- login prompt

[CameronByers]

Hello,

We have a 10.6.1 Portal environment which is stable, federated, with web adaptors configured, etc.

Once users typically log in via our regular <server name.domain>/portal  URL, they can publish and view items freely.

A few days ago, I set up an alias for our site. Reconfigured the SSL certificate to accept the new Alias, had our internal DNS register the new alias, set up new bindings so the alias redirect works, and added the new alias to both the ArcServer web adaptor and Portal web adaptor (Server and Portal are hosted on same machine).

The Alias works- however- whenever a user attempts to publish, they now have to login a 2nd time via a small prompt window that states the original Portal URL with the fully qualified machine name. It works after they log in again, but I'd like to get rid of that extra login window if I can.

Any ideas on what needs to be done to remove that?

[AntigoniKoffa]

Hello,

I am not sure if it will work, but one thing that you could try is setting the WebContextUrl of your portal to the alias URL. Sign in to the ArcGIS Portal Directory as a member of the default administrator role in your portal organization. The URL is formatted https://portal.domain.com:7443/arcgis/portaladmin.
    Click System > Properties > Update Properties.
    On the Update System Properties dialog box, insert the following JSON, substituting your DNS alias URL

    {
       "WebContextURL": "<alias>"
    }

[WilliamCraft]

This sounds like it could possibly be a loopback issue.  Try disabling the server's loopback check using the following Powershell:

New-ItemProperty HKLM:\System\CurrentControlSet\Control\Lsa -Name "DisableLoopbackCheck" -Value "1" -PropertyType dword‍‍