Ssh – allow ssh connection from remote host

puttysshssh-tunnel

I've just started playing around with SSH tunnels today, but I'm stick at a bit of a silly point (I think)… Probably just missing something obvious but here goes:

I've got two linux servers and a single windows client (server1, server2, client). I've set up server1 to create a reverse ssh tunnel to server2, like so:

ssh -nNfR 8022:localhost:22 user@server1

After which I can successfully get a shell on on server1 using:

ssh -p 8022 localhost

Logically, this leads me to think that I should be able to create a putty ssh connection to server1:8022 and get a shell for server2, but I get a connection refused error. Anyone know what I'm missing or am I entirely on the wrong track 🙂

Thanks

Best Answer

This is a common problem. You need to enable port access on the server. Modify GatewayPorts to yes in /etc/ssh/sshd_config.

see man sshd_config under GatewayPorts.

You may also need to specify a bind address to your tunnel setup:

ssh -nNfR *:8022:localhost:22 user@server1

to bind to all interfaces.

see man ssh under -R