SSH Tunnelling is an excellent way to tunnel insecure protocols through a secure communication channel. In this example, I’ll tunnel POP3 traffic using SSH. Traditional POP3 traffic, including username and password information, travels clear-text across the network.
The syntax: ssh -f -N -L <local port>:<remote server>:<remote port> <userid>@<remote server>
To tunnel POP3 traffic using ssh:
- Make sure an ssh client is installed on your machine and an ssh server is installed on the POP3 server.
- Create a local SSH Tunnel on your machine (port 1234 for this example) to the POP3 server’s port 110. You will need to be the root user to bind to “privileged” ports (< 1024).
# ssh -f -N -L 1234:localhost:110 user@POP3_server
- Test the tunnel.
$ telnet localhost 1234
You should see the POP3 server’s banner information.est the tunnel.
- Configure your mail client to access your mail via POP3 using mail server localhost and port 1234.