A colleague of mine sent me a cool little command to create, a “quick and dirty vpn over ssh”:

It’s a quick and dirty vpn over ssh and only requires that ssh and pppd are installed on each end (generally true for Lunix and *BSD)

pppd updetach noauth passive pty “ssh -x -P 123.45.2.55 -l root sudo pppd nodetach notty noauth proxyarp” 192.168.0.65:192.168.0.66 && route add -net 192.168.0.64/26 dev ppp0

Although this has been around for a while it does allow for an ad-hoc virtual private network without the need to install any special VPN software.