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

Using a Neutron router


If you recall from Chapter 3, Neutron API Basics, users can create and manage networks known as tenant networks that are completely isolated from other networks and tenants via Layer 2 segregation. Users do not require any knowledge of the physical infrastructure when creating tenant networks and are not aware of the underlying Layer 2 technology that provides connectivity between hosts, be it VLAN, VXLAN, GRE, or some other technology.

Users can use Neutron routers to provide flexibility in networking by connecting user-created tenant networks to one another and to the physical network. Neutron routers act as NAT gateways in an effort to provide connectivity to and from virtual machine instances in tenant networks. In the following diagram, a Neutron router is connected to both a provider network and a user-created tenant network:

When instances are placed behind a Neutron router, users can no longer access them directly by their fixed IP. Instead, users must create...