Book Image

Learning OpenStack Networking (Neutron)

By : James Denton
Book Image

Learning OpenStack Networking (Neutron)

By: James Denton

Overview of this book

OpenStack Neutron is an OpenStack component that provides networking as a service for other OpenStack services to architect networks and create virtual machines through its API. This API lets you define network connectivity in order to leverage network capabilities to cloud deployments. Through this practical book, you will build a strong foundational knowledge of Neutron, and will architect and build an OpenStack cloud using advanced networking features. We start with an introduction to OpenStack Neutron and its various components, including virtual switching, routing, FWaaS, VPNaaS, and LBaaS. You’ll also get hands-on by installing OpenStack and Neutron and its components, and use agents and plugins to orchestrate network connectivity and build a virtual switching infrastructure. Moving on, you’ll get to grips with the HA routing capabilities utilizing VRRP and distributed virtual routers in Neutron. You’ll also discover load balancing fundamentals, including the difference between nodes, pools, pool members, and virtual IPs. You’ll discover the purpose of security groups and learn how to apply the security concept to your cloud/tenant/instance. Finally, you' ll configure virtual private networks that will allow you to avoid the use of SNAT and floating IPs when connecting to remote networks.
Table of Contents (21 chapters)
Learning OpenStack Networking (Neutron) Second Edition
About the Author
About the Reviewers

Visualizing traffic flow when using LinuxBridge

While an Ethernet frame travels from the virtual machine instance to a remote physical network, it passes through three or four of the following devices depending on the network type:

  • The tap interface: tapN

  • The Linux bridge: brqXXXX

  • The VXLAN interface: vxlan-Z (where z is the VNI)

  • The VLAN interface: ethX.Y (where X is the interface and Y is the VLAN ID)

  • The physical interface: ethX (where X is the interface)

To help conceptualize how Neutron uses Linux bridges, a few examples of LinuxBridge architectures are provided in the following sections.


Imagine a basic OpenStack cloud that consists of a single network on VLAN 100 for use with instances. The network architecture within the compute node resembles the following:

Figure 4.6

In Figure 4.6, three virtual machine instances are connected to a Linux bridge named brqXXXX via their respective tap interfaces. When an instance was launched in the network mapped to VLAN 100, a virtual interface named...