ArcGIS Server 10.3.1
When I try to configure a portal using my web adaptor "Portal URL = https://machine.domain.com:7443" I get the error:
Failed to get administrator token from Portal. Please verify that the Portal URL specified can be accessed successfully.
I'm confused: how can I successfully access the Portal URL when the Web Adaptor cannot create the URL?
What am I missing? TIA
I had similar problem but resolved with ESRI support's help. I was upgrading my Portal for ArcGIS Server from 10.4 to 10.5 and getting this error when configuring the Web Adaptor for the Portal. Since my Portal for ArcGIS Server is integrated with the Active Directory, I used a domain account which has the Portal admin privilege to complete the Web Adaptor configuration. Afterward, I changed the password of the initial portal administrator account (not domain account) and subsequently was able to configure the Web Adaptor with no error. It is possible that the password I used was incorrect.
Copy the administrative Portal URL (https://machine.domain.com:7443 ) into a new tab on the Web Adaptor machine. Are you able to access the home page for Portal? Are you able to sign in from there with the Primary Site Admin account?
If you cannot reach the Portal home page from the machine hosting your Web Adaptor, you will not be able to register the Web Adaptor with the site. If you get a "site cannot be reached" message when trying to access Portal, you will need to work with your IT to make sure there are not firewall restrictions blocking communication between these two machines.