Summary

In this chapter we have set up a secure OpenVPN connection between two partners based on certificates and using strong encryption plus some non-standard security features. In the next step we configured a Debian system with a firewall, which was the Shorewall that offers a nice GUI together with Webmin. A short look at the configuration files of the Shorewall Firewall and possible troubleshooting hints followed before we proceeded with the SuSEfirewall of OpenSuSE. After that we configured two different firewall systems that could connect to each other through the secure OpenVPN tunnel. We looked at iptables, and finally learned how to configure the Windows Firewall on Microsoft Windows XP.