I'm looking for a way to have the server allocate an available port number when using remote port forwarding. In draft-ietf-secsh-connect-25.txt such a feature is described but I fail to see if/how this is actually supported by openssh. Quote from the draft: If a client passes 0 as port number to bind and has 'want reply' TRUE then the server allocates the next available unprivileged port number and replies with the following message, otherwise there is no response specific data. Naively doing things like -R0:host:hostport fail with a "Bad forwarding port(s)" message. Thanks, Wim.
Wim Livens wrote:> I'm looking for a way to have the server allocate an available port > number when using remote port forwarding. > > In draft-ietf-secsh-connect-25.txt such a feature is described but I > fail to see if/how this is actually supported by openssh. > > Quote from the draft: > > If a client passes 0 as port number to bind and has 'want reply' > TRUE then the server allocates the next available unprivileged port > number and replies with the following message, otherwise there is > no response specific data. > > Naively doing things like -R0:host:hostport fail with a "Bad > forwarding port(s)" message.This isn't supported at present, but there is a patch that we will probably look at in the next release cycle: http://bugzilla.mindrot.org/show_bug.cgi?id=1003 -d