This is the scenario: ArcGIS Enterprise 10.5.1, deployed in a single machine deployment, except Web Adaptor, that is installed in another web server. ArcGIS Server was federated with Portal using the internal server names. Later, the deployment was required to be accesed from the internet. A new URL was created, certificates are in order, WebContextURL was set. The problem is when triyng to login to ArcGIS Server, login is redirected to the portal´s internal URL (web adaptor web server name), and fails if accesed from internet. How can I solve this? In ArcGIS Server admin interface, is not posible to update the portalURL value. Re-Federate ArcGIS Server is not possible, and is not recommended.