Download: Stable · Snapshot | Docs | Changes | Wishlist
PuTTY 0.77 introduced the feature of
proxying a network connection over a secondary SSH session, by means
of connecting to a proxy SSH server and asking to open a
direct-tcpip channel to the ultimate endpoint. (This is
the same way that
plink -nc operates, and also the same
thing done by OpenSSH if you use its corresponding
We've now extended this further, by adding the option to ask the SSH server to run a particular command, instead of making a TCP connection directly. So if you can only contact your destination server by SSHing to a proxy host and having that host run a complicated command to make the connection, then now you can set that up conveniently in PuTTY.
Put another way: where the previous SSH proxying feature was a more
convenient alternative to configuring
plink %proxyhost -nc
%host:%port as a local proxy command, the new one is an
alternative to configuring
A few examples of why this might be useful:
The new feature also permits you to invoke an SSH subsystem of your choice, as well as a command. However, the interaction with the subsystem is expected to consist of only the forwarded network traffic, with no prior handshake signalling the destination host. So this will only be useful if you've already configured a subsystem that connects to that specific host, or if your server supports a whole family of subsystems which have the host and port baked into the subsystem name.