Book Image

Learning OpenStack Networking - Third Edition

By : James Denton
Book Image

Learning OpenStack Networking - Third Edition

By: James Denton

Overview of this book

OpenStack Networking is a pluggable, scalable, and API-driven system to manage physical and virtual networking resources in an OpenStack-based cloud. Like other core OpenStack components, OpenStack Networking can be used by administrators and users to increase the value and maximize the use of existing datacenter resources. This third edition of Learning OpenStack Networking walks you through the installation of OpenStack and provides you with a foundation that can be used to build a scalable and production-ready OpenStack cloud. In the initial chapters, you will review the physical network requirements and architectures necessary for an OpenStack environment that provide core cloud functionality. Then, you’ll move through the installation of the new release of OpenStack using packages from the Ubuntu repository. An overview of Neutron networking foundational concepts, including networks, subnets, and ports will segue into advanced topics such as security groups, distributed virtual routers, virtual load balancers, and VLAN tagging within instances. By the end of this book, you will have built a network infrastructure for your cloud using OpenStack Neutron.
Table of Contents (16 chapters)

VLAN-aware VMs

VLAN tagging is a method in which a VLAN tag is added to an Ethernet header to help distinguish traffic from multiple networks carried over the same interface. In the architectures described so far in this book, an instance connected to multiple networks has a corresponding interface for each network. This works at small scale, but PCI limitations may cap the number of interfaces that can be attached to an instance. In addition, hot-plugging interfaces to running VMs when attaching new networks may have unexpected results.

The following diagram visualizes the concept of one vNIC per network:

Figure 14.1

In Figure 14.1, a single vNIC is associated with a Neutron port. Neutron typically performs VLAN tagging at the virtual switch based on the segmentation_id provider attribute of the respective VLAN network. In this case, instances are not expected to perform any...