Non-transparent proxies are generally a complete nuisance at the best of times and huge consumers of time and IT resources at their worst. Sadly proxies are a popular feature in corporate IT networks, so it’s not always possible to avoid them entirely.
Ideally the administrators will have the HTTP/S proxy running transparently, so that users never need to know or configure proxy settings for browsers or other HTTP using applications.
Unfortunately some networks also make use of SOCKS proxies, to block all outgoing TCP and UDP connections unless otherwise authorised. Whilst the feature set of SOCKS is very similar to a firewall, unlike a firewall it’s not network transparent and your applications need to be aware of it and configured to use it.
There’s a lot of information on the web about configuring SSH to *create* a SOCKS proxy, but not a lot about how to use SSH *via* a SOCKS proxy. Because I don’t want to waste any more minutes of my life on the mind-numbing pain that is proxies, the following is the easy command to open an SSH connection through a proxy server:
ssh -o ProxyCommand='nc -x myproxyserver.example.com:1080 %h %p' \ targetsshserver.example.com