Welcome to the new age of network engineering. When I first started working as a network engineer 18 years ago, at the turn of the millennium, the role was distinctly different than other technical roles. Network engineers mainly possessed domain-specific knowledge to manage and operate local and wide area networks, while occasionally crossing over to systems administration, but there was no expectation to write code or understand programming concepts. This is no longer the case. Over the years, the DevOps and Software-Defined Networking (SDN) movement, among other factors, have significantly blurred the lines between network engineers, systems engineers, and developers.
The fact that you have picked up this book suggests that you might already be an adopter of network DevOps, or maybe you are considering going down that path. Maybe you have been working as a network engineer for years, just as I was, and want to know what the buzz around the Python programming language is about. Or you might already be fluent in Python but wonder what its applications are in network engineering. If you fall into any of these camps, or are simply just curious about Python in the network engineering field, I believe this book is for you:
Many books that dive into the topics of network engineering and Python have already been written. I do not intend to repeat their efforts with this book. Instead, this book assumes that you have some hands-on experience of managing networks, as well as a basic understanding of network protocols and the Python language. You do not need to be an expert in Python or network engineering, but should find that the concepts in this chapter form a general review. The rest of the chapter should set the level of expectation of the prior knowledge required to get the most out of this book. If you want to brush up on the contents of this chapter, there are lots of free or low-cost resources to bring you up to speed. I would recommend the free Khan Academy (https://www.khanacademy.org/) and the Python tutorials at: https://www.python.org/.
This chapter will pay a very quick visit to the relevant networking topics. From my experience working in the field, a typical network engineer or developer might not remember the exact TCP state machine to accomplish their daily tasks (I know I don't), but they would be familiar with the basics of the OSI model, the TCP and UDP operations, different IP headers fields, and other fundamental concepts.
We will also look at a high-level review of the Python language; just enough for those readers who do not code in Python on a daily basis to have ground to walk on for the rest of the book.
Specifically, we will cover the following topics:
- An overview of the internet
- The OSI and client-server model
- TCP, UDP, and IP protocol suites
- Python syntax, types, operators, and loops
- Extending Python with functions, classes, and packages
Of course, the information presented in this chapter is not exhaustive; please do check out the references for further information.
