Keeping it simple - they RDP into a host called "coffee".
So, a terminal server sesison connects to "coffee". This works on the LAN resolving to 192.x.x.x and works remotely connecting to 25.x.x.x
However, yesterday he was on a hotspot where the LAN settings/DNS would bounce the host coffee to 127.0.53.53 which is ARPA atandards for "oy - get your name right" - and hence it would not connect.
Connecting to the IP 25.x.x.x works fine.
But clearly all his shortcuts to the hosts that connect to (say) "coffee" do not work and its treated as a new host.
Yes, we could add entry in local hosts, but that would resolve even when on the LAN.
How do you manage a single name for a host?
All I can think of is forcing internal DNS to resolve coffee.myco.com to 192.x.x.x and external DNS to 25.x.x.x but thats a right pain (and they don't have internal DNS server except router that can't do this)