Summary

To repeat a theme, just installing a firewall is not going to secure your network. Testing the firewall rules, the placement of networks, and the physical infrastructure are all components in building an effective security modelalong with other elements of security and risk management discussed throughout this book. If there is any theme you should take from this chapter, it's that you should always test everything rigorously whenever you make a change. Challenge your assumptions and whenever possible, use third parties to review your work!