In my opinion, network security is a tricky topic to write about. The reason is not a technical one, but rather to do with setting up the right scope. The boundaries of network security are so wide that they touch all seven layers of the OSI model. From layer 1 of wiretapping to layer 4 of the transport protocol vulnerability, to layer 7 of man-in-the-middle spoofing, network security is everywhere. The issue is exacerbated by all the newly discovered vulnerabilities, which sometimes seem to be at a daily rate. This does not even include the human social engineering aspect of network security.
As such, in this chapter, I would like to set the scope for what we will discuss. As we have been doing up to this point, we will primarily focus on using Python for network device security at OSI layers 3 and 4. We will look at Python tools that we can use to...