Using an SSH tunnel allows one to establish a secure route from your machine to a remote machine and pipe your traffic to it as if you are at said machine.

The machine that you SSH into is typically called:

  • SSH gateway
  • bastion host
  • jump host/box
  • proxy host
  • relay host

Reasons you may want to use an SSH tunnel could include:

  • you don’t have access to a network from your machine, but have access to an SSH host that does
  • your jump host has a certian type of access that you want to make use of, such as a VPN tunnel

How to do it

In this example we will be trying to use a VPN tunnel on the jump host.

Jump host

Ensure that your jump host has the SSH service running.

Client machine

On Linux, Mac or Windows, in a terminal, run:

1

$ ssh -D 1080 -N -v <username>@<host>

This should establish the tunnel from your local host on port 1080 to the jump host. To test the tunnel, try to reach a host that only your jump host has access to with something like:

$ curl --socks5 127.0.0.1:1080 https://icanhazip.com

# output
123.4.5.6

You could run all subsequent TCP traffic through this bastion host with a tool like proxychains on *nix, or, on all platforms, you can configure your browser to send traffic via this proxy.

There are two ways you could accomplish this:

:hackeremoji