On the client:

Setting up an SSH VPN involves using SSH tunneling to create a secure connection between your local machine and a remote server, effectively acting as a VPN. Here's how to do it:

Basic SSH Tunnel (SOCKS Proxy)

This creates a local SOCKS proxy that routes traffic through the remote server.

Command:

ssh -D 1080 -C -N user@remote-server

• -D 1080: Opens a SOCKS proxy on local port 1080.
• -C: Enables compression (optional).
• -N: Runs without executing a remote command (just forwards ports).
• user@remote-server: Your SSH credentials.

Usage:

• Configure your browser/system to use a SOCKS proxy at 0.0.1:1080.
• All traffic will route through the remote server.

Full Tunnel (Route All Traffic)

For a full VPN-like experience, use SSH with tun devices.

Requirements:

• Root access on the remote server.
• tun kernel module enabled (modprobe tun).

Steps:

On the Server:

Edit /etc/ssh/sshd_config and ensure:

PermitTunnel yes
PermitRootLogin yes

Then restart SSH:

sudo systemctl restart sshd

On the Client:

sudo ssh -w 0:0 -o Tunnel=ethernet user@remote-server

• -w 0:0: Allocates tun0 on client and server.
• -o Tunnel=ethernet: Sets up an Ethernet-like tunnel.

After Connection:

Configure IP addresses:

sudo ip link set tun0 up
# On the server:
sudo ip addr add 10.0.0.2/24 dev tun0
sudo ip link set tun0 up

Route Traffic:

On the client, route all traffic:

sudo ip route add default via 10.0.0.2

Persistent SSH VPN (autossh)

To keep the connection alive:

autossh -M 0 -D 1080 -C -N user@remote-server

• -M 0: Disables monitoring (or use a port like -M 20000).

Notes:

• Security: SSH VPNs are encrypted but may not be as performant as OpenVPN/WireGuard.
• Firewall: Ensure the remote server allows SSH (port 22).
• Alternative: For a more robust VPN, consider OpenVPN or WireGuard.

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