Which SSH config option stops me from SSH'ing through a SSH tunnel?

Question

I am trying to connect directly to a my work computer (work) which is only available via an outside server (outside).

So, the network path is: home » outside » work

Ideally, this should work:

home$ ssh -f -N -L2222:work.example.com:22 outside.example.com
home$ ssh localhost -p 2222  ## This just hangs

It doesn't, though. I can also replace work.example.com with an entirely different server, with the same result. The steps are correct, because I can use the same logic to connect to the work host's web server:

home$ ssh -f -N -L10080:work.example.com:80 outside.example.com
home$ lynx http://localhost:10080/  ## work's pretty web page is displayed 

Also, I can SSH to work if I log into outside first:

home$ ssh outside.example.com
outside$ ssh work.example.com
work$  ## Yay, success!

Finally, this also works in a scenario with different servers involved:

home$ ssh -f -N -L2222:different.example.com:22 another.example.com
home$ ssh localhost -p 2222
different$  ## Success!

So, I guess there's some SSH configuration on outside that stops me from using the direct approach, since this works with different servers.

Home runs OpenBSD 4.6 with OpenSSH_5.3. Outside runs MacOSX 10.7.2 with OpenSSH_5.6p1. Work runs CentOS 6.0 with OpenSSH_5.3p1.

EDIT: The solution glared straight at me as I came to work today. Little Snitch (a firewall) had been blocking my connections, and had cheerfully opened quite a few "Do you want to allow this connection" dialogues. Thanks for the help; I'm granting @golimar the correct answer for this one, since it was a pretty plausible solution.

Answer 1

It's probably the options AllowTcpForwarding and/or GatewayPorts in the sshd_config file in "outside"

If that's the case, your ssh client should say something about it (in a log file or with the verbose option). I saw this in Putty on windows so I can't tell what the ssh command does...