In this chapter, we have built a layered architecture to serve the requirements of the potential variety of scenarios that we might encounter. We started the chapter with a layered approach to meet the needs of our external testing.

Following the defined layers, we began with adding the required components to each of the segments of the architecture. We also looked at the filtering and routing requirements and built and configured both a Cisco router emulator as well as an iptables machine to meet our filtering requirements.

Once we configured and tested our first layer components, we moved to the task of adding a firewall to the architecture. We used the popular tool Smoothwall as our firewall and configured it to support one service for testing purposes.

After we built the firewall and tested the configuration, we next took on the task of adding monitoring capability to the range. We built and configured Snort on all three required subnets to support our need for intrusion detection...