View source for Connect to laptop (behind NAT) using intermediary server

[[Category:Networking]]

== Introduction ==

We'll use a combination of ssh remote and local port forwarding in order to expose the laptop's ssh port outside the NAT. The laptop must initiate the forwarding.

== On the server ==

Make sure you have an account that the laptop can connect to through ssh.

== On the laptop ==

This will initiate a connection to the server (from the laptop), and it will set-up a remote port forward such that dialing localhost:12345 '''on the server''' will forward to localhost:22 on the laptop.

 ssh -N -R 12345:localhost:22 harieta@freedom.mgk.ro

== On the other client ==

This will connect to the server, and then set-up a local port forward (from the ''other client'' to the server) such that dialing localhost:12345 '''on the client''' will connect to localhost:12345 '''on the server'''. Of course, localhost:12345 on the server just forwards to localhost:22 on the laptop.

 ssh -N -L 12345:localhost:12345 freedom.mgk.ro

Then from another terminal (still on the other client) you can

 ssh -p 12345 ubuntu@localhost

And should reach localhost:22 '''on the laptop'''.

== References ==

* [https://man.openbsd.org/ssh.1 ssh(1)]