A very simple post about setting up reverse SSH tunneling. This is how to get to a machine that maybe behind a firewall, when you are not behind the firewall (though you need to be to set it up!)

We have two machines: remote.edu is our machine that is behind the firewall, and local.edu is our machine that we are working on. Ordinarily, we can ssh from remote.edu to local.edu but we can not ssh the other way, because remote.edu is behind a firewall.

First, we ssh from remote.edu to local.edu and tell remote.edu to listen on one of the unused ports:

remote.edu:~ $ ssh 44444:localhost:22 redwards@local.edu

This will log you into local.edu like normal. Now, we switch over to local.edu and ssh to remote.edu. However, since we have the connection open, we tell local.edu to just ssh to port 44444:

local.edu:~ $ ssh -p 44444 localhost

This will log you back into remote.edu and you are connected! Reverse tunneling in a snap