reverse-ssh-tunnel

Requires: autossh

Bash script to establish an automatic and permanent SSH tunnel with reversed port forwarding.

This allows connections to a remote (public) host to be forwarded to a host behind a NAT in the local network.

Disconnections and re-connections will be gracefully handled by autossh. For this to work you should setup authentication using SSH keys.

It does the following:

1. Establishes an SSH connection to REMOTE_HOST;
2. binds one or more REMOTE_PORTs in REMOTE_HOST;
3. forwards incoming connections from
   REMOTE_HOST:REMOTE_PORT
   to
   LOCAL_HOST:LOCAL_PORT.

Note: In order to bind REMOTE_PORTs to all interfaces in REMOTE_HOST, you may need to add 'GatewayPorts yes' to the sshd configuration of REMOTE_HOST. Remember to restart the sshd daemon after making changes to its configuration.
Failing to do this may result in the tunnel refusing external connections.

Also, LOCAL_HOST is relative to the host where you run this script from, and it can either be localhost itself, or any other host accessible by it, for example another machine in the LAN.

Default configuration forwards REMOTE_HOST:8880 to LOCAL_HOST:80 and REMOTE_HOST:8443 to LOCAL_HOST:443.

Copyright (C) 2015-2019 Filipe Farinha - All Rights Reserved

Permission to copy and modify is granted under the GPLv3 license