Setup Linux Network Bridges on CentOS for Nova Networking

If you're using Platform9 Managed OpenStack with Nova Networking, Platform9 requires one or more Linux bridges on your Linux servers. The network bridges are used in networking for Virtual Machines. This tutorial will guide you through a step-by-step process to create Linux bridges on CentOS servers.

IMPORTANT: If using Platform9 Managed OpenStack with Neutron Networking,  follow Neutron Pre-requisites for Linux/KVM to prepare your physical servers.

Step 1 - Install Prerequisites

Install required packages  needed for Linux bridge.

If using CentOS version 6.x or below:

sudo yum install bridge-utils
sudo yum install tunctl

If using CentOS version 7.x:

sudo yum install bridge-utils

Step 2 - Disable Network Manager

NetworkManager does not support bridging and therefore must be disabled to setup Linux bridge networking.

chkconfig NetworkManager off
chkconfig network on
service NetworkManager stop
service network start

NOTE: Alternatively, you can add "NM_CONTROLLED=no" to the ifcfg-* script below, and then you do not have to turn off NetworkManager.

Step 3 - Create A Bridge Configuration File

A good convention to follow is to name your Linux bridge after the VLAN to which the bridge is being mapped to (if any). Create file /etc/sysconfig/network-scripts/ifcfg-

vi /etc/sysconfig/network-scripts/ifcfg-<your-bridge-name>

Edit the file you just created and add the following parameters along with appropriate values:

DEVICE=<your-bridge-name>
TYPE=Bridge
BOOTPROTO=<boot-protocol-from-network-interface>
DNS1=<your-dns-address>
GATEWAY=<your-gateway-address>
IPADDR=<ip-address-from-network-interface>
NETMASK=<your-netmask>
ONBOOT=yes
SEARCH=”example.com”

Step 4 - Make Your Network Interface Slave To The Bridge Interface

Assuming you would like to map eth0 interface to this bridge, edit the network script file and add following line to it.

# this makes the network interface slave to the bridge
BRIDGE=<name-of-bridge-just-created>

Step 5 - Restart Networking

You must now restart networking or reboot OS to make the changes reflect.

sudo service network restart

Step 6 - Network Discovered By Platform9

At this point, your bridge device is successfully configured. If this server has been added to Platform9, the new bridge device will be discovered as a new network by Platform9 within few minutes, and reported as part of the 'Network' tab in Infrastructure view.


November 20, 2015