ssh tunnelling chain
ssh, tunnel, windows
Solution
In OpenSSH, I use this setup when I need tunnels. This allows me to directly type `sftp server3` without having to worry about manually starting the `server2` and `server1` tunnels first.
# ~/.ssh/config
# to connect to server2, tunnel through server1
Host server2
ProxyCommand ssh server1 nc %h %p
# to connect to server3, tunnel through server2
Host server3
ProxyCommand ssh server2 nc %h %p
To be more complete, I usually use `ssh -oCiphers=arcfour128,arcfour256,arcfour,blowfish-cbc -oControlMaster=no -oForwardX11=no -oForwardAgent=no -oPermitLocalCommand=no -oClearAllForwardings=yes server1 nc %h %p` as the `ProxyCommand`.
- The ssh connection being tunneled is already encrypted, so there's no point in using the heavier `aes`/`3des` for the outer layer; `arcfour` and `blowfish` are faster.
- The rest of the `-o****` settings are out of paranoia, so that nothing breaks even if a `Host server1` stanza with really odd settings is added to `ssh_config`.
Similarly, you can configure PuTTY to use the proxy command `plink -P %proxyport -pw %pass %user@%proxyhost nc %host %port`, and set the proxy hostname/port/user/password in the Connection/Proxy configuration pane accordingly. `plink` and the rest of the PuTTY suite (`pscp`, `psftp`, etc.) load anything saved in PuTTY's graphical configuration; hopefully WinSCP does too. (I don't use it, so I'm not too familiar with its features.)
Problem
Here is the scenario I am trying to get scp access to server3, but there is only public ssh access to server 1. To ssh to server3, I have to ssh to server1, ssh to server2, then ssh to server3. My hopeful end result would be that I could WinSCP to localhost:8022 and it will give me file access to server3. I am trying to use ssh tunnels, but through all the tutorials and questions I have read none seem to work for this scenario. I am using putty on Windows. Any suggestions would be truly helpful. Thank you.