Chapter 5. Low-Level Network Device Interactions

In this chapter, we will start to dive deeper into the management of network devices using Python. In particular, we will examine the different ways in which we can use Python to programmatically communicate with legacy network routers and switches.

What do I mean by legacy network routers and switches? While it is hard to imagine any networking device coming out today without an Application Program Interface (API) for programmatic communication, it is a known fact that many of the network devices deployed in previous years did not contain API interfaces. The intended method of management for those devices was through Command Line Interfaces (CLIs) using terminal programs, which were originally developed with a human engineer in mind. The management relied on the engineer's interpretation of the data returned from the device for appropriate action. As the number of network devices and the complexity of the network grew, it became increasingly...