vnc connection working with PuTTY but not with command line

Question

I am using PuTTY to connect to a distant network to then set up x11vnc and then using ssl/sshvnc as a client.

in the host name for PuTTY I have: ssh.inf.uk

and port: 22

in the ssh tunnel options I have source port set to: 5910

and destination: markinch.inf.uk

Then putty brings up an xterm and I am prompted for my username and password. I get to the common gateway machine and do

ssh markinch

then I set up the x11vnc server

x11vnc -ssl -usepw -rfbport 5910 -create -geometry 1200x800

I use ssl/ssh vnc viewer with the verify certs off and host port set to, localhost:10 and put the password, and connect fine.

---Now I want to bypass usuing PuTTY, and do the ssh connection via command line. So I do

 ssh -L localhost:5910:ssh.inf.uk:5910 [email protected]

which brings me into the gateway machine, then I need to log into a specific desktop

 ssh -L localhost:5910:markinch.inf.uk:5910 markinch

Then I set up the x11vnc server,

x11vnc -ssl -usepw -rfbport 5910 -create -geometry 1200x800

then I use ssl/ssh vnc viewer with verify certificates off, localhost:10, and with the password in, and get: PORT=5910

SSLPORT=5910

channel 3: open failed: connect failed: Connection refused

What is putty doing so different? Best,

Answer 1

In your putty config, the traffic is exiting the tunnel at ssh.inf.uk and being forwarded directly to markinch.inf.uk. So you're only building 1 tunnel.

In your ssh statements, you're building 2 tunnels - one from localhost to ssh.inf.uk, and a second from ssh.inf.uk to markinch.inf.uk.

I haven't yet worked out why the 2-tunnel solution isn't working for you. However, you might try adjusting your ssh command to match what putty's doing and see if that works.

  ssh -L localhost:5910:markinch.inf.uk [email protected]