Forwarding Internet connection via SSH to a Linux console
Solution 1:
As long as your client can SSH to the server, there's really not much you can't do - provided that the server doesn't block ports.
With dynamic port forwarding you can create a socks5 proxy on localhost, using something like this:
ssh -NTf -D 1080 user@server
Now you can point your applications like web browsers to the socks proxy at 127.0.0.1:1080
.
Another tool you could consider is sshuttle. To tunnel all your web traffic (including those programs that don't support proxies like package managers) you can use a command like this:
sshuttle -r user@server 0/0
Also consider asking the sysadmin there to just open the appropiate ports, as they may not be pleased with users attempting to bypass their firewall rules..