In this chapter, we built a systematic step-by-step process for when we performed assessments against a variety of devices. We started the chapter with the router device, and then we moved on to the switches. Following the routers and switches, we moved on to a discussion on what to do when we encounter firewalls.

Once we learned how to deal with a number of different devices, we moved on to methods to identify the filtering rules that are in place. We discovered how and when a scan is conducted against certain devices, they will respond not in accordance with the standards as set forth in the RFC; furthermore, we were able to discover that when there is a rule in place on a device, it is common for that one port to have a response that provides us with additional details on how to proceed against that device.

Finally, we closed the chapter with a discussion on tricks to penetrating filters, and we looked at using a fragmentation scan; however, this did not provide much success. Then...