SSH Port Forwarding:Overview

SSH Port Forwarding Overview

This document describes the SSH port forwarding system architecture and how it works.

Configuration File: /etc/ssh-port-forwards.conf

   Defines all SSH port forwards in a simple format
   One device per line

Management Script: /usr/local/bin/ssh-port-forward-manager.sh

   Adds, removes, and lists SSH port forwards
   Applies iptables rules automatically
   Validates configurations

Integration: /etc/openvpn/iptables-restore.sh

   Automatically applies all port forwards when VPN starts
   Ensures rules persist after reboots

How It Works

External Client → VPS:EXTERNAL_PORT (e.g., 22222)
  → iptables DNAT rule
  → VPN Tunnel (tun0)
  → VPN_DEVICE:SSH_PORT (e.g., 10.8.0.2:22)

Current Configuration

To see the current configuration:

cat /etc/ssh-port-forwards.conf

To see active iptables rules:

= View DNAT rules =
iptables -t nat -L PREROUTING -n -v | grep DNAT

= View FORWARD rules =
iptables -t filter -L FORWARD -n -v | grep -E "10\.8\.0\."

Related Documentation

[[Documentation:Configuration](Configuration|- Configuration file format [Management]])(management.md) - Managing port forwards Troubleshooting - Troubleshooting guide