Book Image

Practical Network Automation

By : Abhishek Ratan
Book Image

Practical Network Automation

By: Abhishek Ratan

Overview of this book

Network automation is the use of IT controls to supervise and carry out every-day network management functions. It plays a key role in network virtualization technologies and network functions. The book starts by providing an introduction to network automation, SDN, and its applications, which include integrating DevOps tools to automate the network efficiently. It then guides you through different network automation tasks and covers various data digging and reporting methodologies such as IPv6 migration, DC relocations, and interface parsing, all the while retaining security and improving data center robustness. The book then moves on to the use of Python and the management of SSH keys for machine-to-machine (M2M) communication, all followed by practical use cases. The book also covers the importance of Ansible for network automation including best practices in automation, ways to test automated networks using different tools, and other important techniques. By the end of the book, you will be well acquainted with the various aspects of network automation.
Table of Contents (14 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

OpenFlow


OpenFlow is a communication protocol that is used for communication between different vendor's equipment for the packet flow. This standard is maintained by a group called Open Network Foundation (ONF). OpenFlow, as the name suggests, is used to control the flow of packets in a network layer through a mix of Access Control Lists (ACLs) and routing protocols.

OpenFlow primarily has two components—controllers and switches. Controllers are used to take decisions in terms of creating a path for the packet to flow across the different connected devices, and switches (or network equipment) are dynamically configured from the controller based upon the path that a packet needs to take.

Going a little more in-depth, OpenFlow controllers control the routing of packets in OpenFlow switch forwarding tables through the modification, addition, or deletion of packet matching rules as decided by the controller.

As OpenFlow is another protocol, it runs over TCP and works on port 6653 on controllers. At the time of writing, OpenFlow standard 1.4 is currently active and being widely used in the SDN framework. OpenFlow is an additional service that proprietary network vendors run alongside their custom software. This, in general, ensures that the data forwarding or data packet handling is still part of proprietary switch, but the data flow or control plane tasks is now taken over by OpenFlow controllers. As part of SDN framework, if a participating switch receives a packet and does not know where to send it, it communicates with the OpenFlow controller for an answer. The controller, based upon its preconfigured logic, decides what action to take for that unknown packet and can get switches that it is controlling to create a separate or a specific path for that packet to flow across the network. Because of this behavior, this is the protocol that is currently being deployed across all deployments where SDN is being introduced.