sshvpn is a simple shell script to establish a secure vpn tunnel

http://sshvpn.sourceforge.net/
“SSHVpn tunnel Creator.
sshvpn is a simple shell script to establish a secure vpn tunnel using openSSH vpn tunneling feature which is available from openssh-4.3 and above. The openssh uses the tun(4) network tunnel device which is available in most platforms either for layer 2 or 3 traffic to create the tunnel. This new vpn tunnel feature is different from portforwarding, where just a service is forwarded.
This script will help to establish a secure bridge between two private network or to attach a single host to the remote network over the internet, like PPTP vpn tunnel.
To enable the ssh server to accept tunnel requests from the client, the following directive should be set on the server configuration.
PermitTunnel yes
Requirements:
Currently this script works with Linux as client and server (the network gateways of the two private network). This can be easily modified to work on other unixvariants.
OpenSSH-4.3 or above server and client.
The linux kernel should have the support for
the tun device.
the netfilter.
either in the kernel or as a kernel module. Most of the Linux distribution that come these days have the support built-in.”