Book Image

Mastering Python Networking

Book Image

Mastering Python Networking

Overview of this book

This book begins with a review of the TCP/ IP protocol suite and a refresher of the core elements of the Python language. Next, you will start using Python and supported libraries to automate network tasks from the current major network vendors. We will look at automating traditional network devices based on the command-line interface, as well as newer devices with API support, with hands-on labs. We will then learn the concepts and practical use cases of the Ansible framework in order to achieve your network goals. We will then move on to using Python for DevOps, starting with using open source tools to test, secure, and analyze your network. Then, we will focus on network monitoring and visualization. We will learn how to retrieve network information using a polling mechanism, ?ow-based monitoring, and visualizing the data programmatically. Next, we will learn how to use the Python framework to build your own customized network web services. In the last module, you will use Python for SDN, where you will use a Python-based controller with OpenFlow in a hands-on lab to learn its concepts and applications. We will compare and contrast OpenFlow, OpenStack, OpenDaylight, and NFV. Finally, you will use everything you’ve learned in the book to construct a migration plan to go from a legacy to a scalable SDN-based network.
Table of Contents (22 chapters)
Title
Humble Bundle
Credits
Foreword
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
12
OpenStack, OpenDaylight, and NFV

Layer 2 OpenFlow switch


While we have lots of choices when it comes to learning and dissecting Ryu OpenFlow applications, we want to pick something simple that we have already worked with. By simple, I mean we want to pick something in which we know how the technology works so we can focus on just the new information, such as how Ryu uses Python to implement OpenFlow technologies. To that end, the Layer 2 OpenFlow switch application that we saw earlier would be a good candidate. Most of us network engineers know how switching works, especially in a single-switch setup (without spanning tree, which is not so simple).

As a reminder, if you are using the SDNHub virtual machine and are logged in as the default user Ubuntu, the application file is located under /home/ubuntu/ryu/ryu/app/simple_switch_13.py:

ubuntu@sdnhubvm:~[21:28]$ ls ryu/ryu/app/simple_switch_13.py
 ryu/ryu/app/simple_switch_13.py 

The file is surprisingly short: fewer than 100 lines of code minus the comments and import statements...