SSH
SSH VPN Syntax
sudo ssh -w 0:0 1.2.3.4
From man page:
-w local_tun[:remote_tun]
Requests tunnel device forwarding with the specified tun(4) devices between the client (local_tun) and the server (remote_tun).
The devices may be specified by numerical ID or the keyword ‘‘any’’, which uses the next available tunnel device. If remote_tun is not specified, it defaults to ‘‘any’’. See also the Tunnel and TunnelDevice directives in ssh_config(5). If the Tunnel directive is unset, it is set to the default tunnel mode, which is ‘‘point-to-point’’.