I have a 2012 R2 RD session host collection with RD Gateway configured and working.
Now I need to have external clients connect to another rdp listener on the session hosts, and have added an extra listener on each host listening on port 3390. All is well on that part.
But I am stuck in what I expected to be the easy part - how do I setup the rdp link in the RD Gateway portal to connect external clients to port 3390 on session hosts?