ssh -R is possible to allocate a free port by specifying '0' while with
ssh -L you need to specify a valid free port?
I want ssh to use a local free port to FWD remote traffic without depending on free ports hacks
From manual pages
If the port argument is ‘0’, the listen port will be dynamically allocated on the server and reported to the client at run time.
But -L doesn't provide that possibility :(
Specifies that the given port on the local (client) host is to be forwarded to the given host and port on the remote side.....