New command-line option in Plink (and PuTTY, though it's less useful

[sgt/putty] / doc / using.but

diff --git a/doc/using.but b/doc/using.but
index 0fb7127..af98d90 100644 (file)
--- a/doc/using.but
+++ b/doc/using.but
@@ -796,6 +796,47 @@ at all} checkbox in the SSH panel of the PuTTY configuration box
 This option is not available in the file transfer tools PSCP and
 PSFTP.
 
 This option is not available in the file transfer tools PSCP and
 PSFTP.
 

+\S2{using-cmdline-ncmode} \I{-nc}\c{-nc}: make a \i{remote network
+connection} in place of a remote shell or command
+
+The \c{-nc} option prevents Plink (or PuTTY) from attempting to
+start a shell or command on the remote server. Instead, it will
+instruct the remote server to open a network connection to a host
+name and port number specified by you, and treat that network
+connection as if it were the main session.
+
+You specify a host and port as an argument to the \c{-nc} option,
+with a colon separating the host name from the port number, like
+this:
+
+\c plink host1.example.com -nc host2.example.com:1234
+
+You might want to use this feature if you needed to make an SSH
+connection to a target host which you can only reach by going
+through a proxy host, and rather than using port forwarding you
+prefer to use the local proxy feature (see \k{config-proxy-type} for
+more about local proxies). In this situation you might select
+\q{Local} proxy type, set your local proxy command to be \cq{plink
+%proxyhost -nc %host:%port}, enter the target host name on the
+Session panel, and enter the directly reachable proxy host name on
+the Proxy panel.
+
+This feature is only available in SSH protocol version 2 (since the
+version 1 protocol assumes you will always want to run a shell). It
+is not available in the file transfer tools PSCP and PSFTP. It is
+available in PuTTY itself, although it is unlikely to be very useful
+in any tool other than Plink. Also, \c{-nc} uses the same server
+functionality as port forwarding, so it will not work if your server
+administrator has disabled port forwarding.
+
+(The option is named \c{-nc} after the Unix program
+\W{http://www.vulnwatch.org/netcat/}\c{nc}, short for \q{netcat}.
+The command \cq{plink host1 -nc host2:port} is very similar in
+functionality to \cq{plink host1 nc host2 port}, which invokes
+\c{nc} on the server and tells it to connect to the specified
+destination. However, Plink's built-in \c{-nc} option does not
+depend on the \c{nc} program being installed on the server.)
+

 \S2{using-cmdline-compress} \I{-C-upper}\c{-C}: enable \i{compression}
 
 The \c{-C} option enables compression of the data sent across the
 \S2{using-cmdline-compress} \I{-C-upper}\c{-C}: enable \i{compression}
 
 The \c{-C} option enables compression of the data sent across the