Setting up an SSH proxy

I was looking at guides for setting up a localhost SSH proxy, but I'm wondering how I would do it for using the Linode as the proxy server.

I realize I'll need to open a port on the firewall on the proxy, and I think the code for that would be:

-A INPUT -p tcp -m state --state NEW --dport 5252 -j ACCEPT

If the port used is 5252.

That's the same as what's used for port 22 for SSH.

I think the main change would be using the domain of the Linode instead of localhost and adding the firewall rule.