I caught this in hopes this might help. Using an airport extreme and another MAC or Windows PC on the same network will work fine.
With your Airport Base Station you will need to open the Airport Utility, Manual configuration to forward port 1194 to the IP address of the Amahi Server xx.xx.xx.xx, select Update and maybe restart your base station and all should be good.
Port mapping on Airport should be as follows:
Public UDP Ports: 1194
Private UDP Ports: 1194
Private IP Address: xx.xx.xx.xx (where this is the IP Address of your Amahi Server)
I have no issue using Viscosity but could not get Tunnelbrick to work. The one thing you will want to do, which worked for me is to go into your directories on your server and copy the key's you generate for SSL, ca, cert et. all to a thumb drive, import those into Viscosity and set it up that way. Use yoursitename.yourhda.com with the VPN client.
Honestly speaking, I have issues with going to
http://hda or
https://hda from a MAC - but not with a PC. Windows and the Amahi VPN client are made for each other. I do not understand why -- but having a similiar set up as you I go into Windows and enter my credentials and connect via VPN client then launch web browser and I can access it via
http://hda or https:/hda and launch any of the applications. I can not do this on a macintosh. Not sure why. I've tried. I have no firewalls or software from blocking it so it should work fine. I've tried it on 3 macintosh computers, I can connect but I have to use the
http://ip address http or
https://xx.xx.xx.xx/user_sessions/new to launch the login screen. Once there I can not launch any of the applications. It seems like a DNS related thing; something fussy with mac, but I will try this on linux.
Everything works fine with Airport's and Windows PC.
PS: If anyone has the answer to the question I pose regarding what I may be doing wrong on my mac I'd love to know. Thank you.