ssh proxy

Using SSH Proxy in .ssh/config

[ Your Machine ] ---> [ Gateway Server ] ---> [ Final Destination ]
      ssh            ProxyCommand/Jump           ssh session

The SSH ProxyCommand and ProxyJump options allow you to route SSH connections through an intermediate server (proxy), — allows SSH to reach otherwise inaccessible targets by hopping through a proxy simplifying firewall rules and enhancing security.

Configuring an SSH Proxy in ~/.ssh/config

To automate proxy connections, add the following to ~/.ssh/config:

Host final-server                                   Copy
    ProxyCommand ssh -W %h:%p user@gateway-server

• ProxyCommand → Uses the gateway server to forward SSH traffic to final-server. — ProxyCommand establishes the link through a jump host or bastion to the destination
• -W %h:%p → Sends raw TCP stream — sends unmodified TCP data directly to the target server over the tunnel to the destination.

Alternative: Using ProxyJump (Simpler)

Host final-server                                   Copy
    ProxyJump user@gateway-server

• ProxyJump → Automatically forwards SSH traffic through the gateway without needing ProxyCommand.