Why can I not connect to a reverse SSH tunnel port remotely, even with GatewayPorts enabled?
Solution 1:
You need to enable GatewayPorts=yes in the config for SSHd (/etc/ssh/sshd_config), not the client in order to enable binding to interfaces other than loopback on remote ports.
-o GatewayPorts=yes
Only works for local ports when passed to the ssh command.