Chapter 10. Network Setup
This chapter provides instruction on configuring networking for the Red Hat Enterprise Virtualization environment. For information about managing networking, including maintenance, refer to the Red Hat Enterprise Virtualization Administration Guide.
Red Hat Enterprise Virtualization uses networking to support almost every aspect of operations. Storage, host management, user connections, and virtual machine connectivity, for example, all rely on a well planned and configured network to deliver optimal performance. Setting up networking is a vital prerequisite for a Red Hat Enterprise Virtualization environment because it is much simpler to plan for your projected networking requirements and implement your network accordingly than it is to discover your networking requirements through use and attempt to alter your network configuration retroactively.
A familiarity with the network concepts and their use is highly recommended when planning and setting up networking in a Red Hat Enterprise Virtualization environment. This document does not describe the concepts, protocols, requirements or general usage of bonds, bridges and logical networks. It is recommended that you read your network hardware vendor's guides for more information on managing networking.
10.1. Determine Network Requirements
It is possible to deploy a Red Hat Enterprise Virtualization environment with no consideration given to networking at all. Simply ensuring that each physical machine in the environment has at least one
Network Interface Controller(
NIC) cabled to a switch and assigned an IP address by DHCP is enough to begin using a Red Hat Enterprise Virtualization environment. While it is true that this approach to networking will provide a functional environment, it will not provide an optimal environment. Because network usage varies by task or action, grouping related tasks or functions into specialized networks can improve performance while simplifying the troubleshooting of network issues. By default, the Red Hat Enterprise Virtualization Manager creates one logical network called
rhevm
and uses this logical network for all traffic.
The
rhevm
network is created and labeled as the
Management logical network. The
rhevm
logical network is intended for management traffic between the Red Hat Enterprise Virtualization Manager and virtualization hosts. Other types of traffic that are common to all Red Hat Enterprise Virtualization environments are:
For the Red Hat Enterprise Virtualization environment to perform optimally, these types of traffic should be separated. This is easily accomplished by assigning each type of network traffic to a different logical network. Each logical network must be associated with a cabled, active network device. The network device that supports each logical network can be physical, a
NIC or logical, like a bond device or virtual NIC(
VNIC).
The number of logical networks that can be defined and implemented in a Red Hat Enterprise Virtualization environment is limited by the number of network interfaces present on the virtualization hosts in the environment. Each logical network needs at least one physical device to support it. Because a logical network must be implemented for each host in a cluster for the logical network to be operational, the number of logical networks that can be implemented in a given cluster is limited by the host in a cluster with the fewest NICs.