Book Image

OpenStack Networking Essentials

By : James Denton, Derek Chamorro
Book Image

OpenStack Networking Essentials

By: James Denton, Derek Chamorro

Overview of this book

The OpenStack Networking API offers users the ability to create and manage both basic and complex network architectures that blend the virtual and physical network infrastructure. This book kicks off by describing various components of Openstack Neutron and installing Ubuntu OpenStack based on Canonical's process. Further on, you will use various methods to interface with Neutron to create and manage network resources. You will also get to grips with the relationship between ports, networks, and subnets through diagrams and explanations, and see how the logical components are implemented via plugins and agents. Moving forward, you will learn how virtual switches are implemented and how to build Neutron routers. You will also configure networks, subnets, and routers to provide connectivity to instances using simple examples. At the end, you will configure and manage security groups, and will observe how these rules translate to iptables rules on the host machines. By the end of the book, you will be able to build basic network architectures using Neutron networks and routers in no time.
Table of Contents (15 chapters)
OpenStack Networking Essentials
Credits
About the Author
www.PacktPub.com
Preface
Index

The basics of routing in Neutron


If you recall from the previous chapter, users can create and manage networks known as tenant networks within their respective project without any knowledge of the underlying infrastructure. By default, instances connected to tenant networks are isolated from other networks and are unable to access external resources such as the Internet. Neutron provides connectivity to instances in tenant networks by way of virtual routers.

Network namespaces

In a reference implementation, virtual routers created in Neutron are implemented as network namespaces that reside on nodes running the Neutron L3 agent service. Network namespaces are similar in function to Virtual Routing and Forwarding (VRF) domains, where multiple instances of a routing table exist to provide complete network segregation in a single device. The use of network namespaces allows Neutron to support overlapping subnets across networks. In Linux, network namespaces can be managed using the ip netns...