'''Important:''' Both sides need to run as root to create the tunnel device. Thus, 'ssh -w 0:0 root@www.hentschel.net' must run as root on the client side too.
<quote>
+---------------+ OpenSSH 4.3 +---------------+
| Machine A | tun0 -- Tunnel Interface -- tun0 | Machine B |
| Has a tunnel | <------------------------------->| Has a tunnel |
| and ethernet | 10.0.0.100 10.0.0.200 | and ethernet |
+-------+-------+ point to point connection +-------+-------+
eth0 | creates a bridge | eth0
10.0.0.100 | that plugs machine B | 192.168.0.100
port 22 | into network A |
forwarded | |
here | |
+-------+-------+ +-~-~-~-~-~-~-~-+ +-------+-------+
| Network A | | | | Network B |
| 10.0.0.1/24 | 1.2.3.4 | The Internet | | 192.168.0.1/24|
| Has internet |<-------->| |<----->| Has internet |
| NAT gateway | Routable | | | NAT gateway |
+---------------+ Address +-~-~-~-~-~-~-~-+ +---------------+
</quote>