Once I had to urgently reach the working grid in order to merge fresh raw materials from CVS, install software to compile, but, alas, it appears that the vpn server has fallen.
Glory I don’t know who, but our admins “just in case” opened one server outwards via ssh with authorization only by keys. That saved me ...
')
Thanks to the creators of 
Dante, I managed to do everything as if I had access to a real VPN and did not disappear at all.
To begin with, I had to install a small dante-client package (mine is Debian, but I don’t think that it would be a problem to install on other Dante distributions):
 sudo aptitude install dante-client 
Edit /etc/dante.conf, add the lines:
 route { from: 0.0.0.0/0 to: 0.0.0.0/0 via: 127.0.0.1 port = 3128 protocol: tcp udp proxyprotocol: socks_v5 method: none } 
... and launch VPN-for-the-poor:
 ssh -D 3128 user@back-door.big-corp.com 
Everything, from now on, to update the raws of the working draft is not a problem at all:
 socksify cvs update -d 
Logging in to the server to start the build is also not a question:
 socksify ssh me@myserver.big-corp.com 
Well, to access corporate resources via http you can use a great addon to Firefox, 
FoxyProxy... The working day is saved! :)