The formidable staff members at OpenOffice in Amsterdam helped me set up a VPN.
Note to Debian and Ubuntu Users
If you install using the .deb, you will find that your /etc/shorewall directory is practially empty. This is intentional. The released configuration file skeletons may be found on your system in the directory /usr/share/doc/shorewall/default-config. Simply copy the files you need from that directory to /etc/shorewall and modify the copies.