I'm working with a server that is behind a firewall. I have established an ssh tunnel to an intermediate server in the internet like this:

remoteuser@behind_fw$ ssh -N -f -R 10002:localhost:22 middleuser@middle

But I can't connect directly throgh this server, this doesn't work:

user@local$ ssh remoteuser@middle -p 10002

I have to connect in two steps:

user@local$ ssh middleuser@middle
middleuser@middle$ ssh remoteuser@localhost -p 10002

Output of netstat -l on middle:

tcp        0      0 localhost:10002         *:*                     LISTEN

but it should be something like this:

tcp        0      0 *:10002                 *:*                     LISTEN

how can I achieve this?