The virtual private network daemon vpnd is a daemon which connects two networks on network level either via TCP/IP or a (virtual) leased line attached to a serial interface. All data transfered between the two networks are encrypted using the unpatented free Blowfish encryption algorithm. Functional overview available here.
You can download it from the following link: https://packetstormsecurity.com/files/download/23162/vpnd-1.1.0.tar.gz
Source: https://packetstormsecurity.com/files/23162/vpnd-1.1.0.tar.gz.html