I am using Teamviewer atm which works great, but I need to change it because of commercial use. I want to connect from my Windows PC at work with PuTTY and UltraVNC Viewer to my Raspberry Pi at home where I am Running openSSH and X11VNC. The challange is hat I have just 443 open. If I try it in an network without a proxy I can reach the Pi via 443 SSH but nothing more. If I am behind a proxy it doesnt work at all, even when typed in the proxy in the settings from PuTTY. So how is Teamviever doing that? Also Ammyy does work (tested with Win8 on the backend)
The Situation:
Client(Win7, behind proxy, only 443 open, PuTTY and UltraVNC) wants to talk to Server(Ubuntu 15, openSSH, X11VNC, DynDNS, port 5900, 443, 22 forwarded to Pi local adress)
Whats the trick to get this running if the client is behind a proxy?
If your client is behind a proxy and you're chatting to the client directly with the given address you're essentially missing a stepping stone. You'll need to acquire the proxies settings and address, and connect to the client with a proxy/client syntax since the proxy is hosting the client. Make sure that the proxy server is allowing your outgoing connection.
You should also consider using DynDNS of sorts to make connecting to a constantly changing address easier.