Edenmal

Sysadmin Garden of Eden

OpenVSwitch: Persistent IP configuration under Rhel based distros

Table of Contents
  1. 1. Preparing for using the interface configurations
  2. 2. Creating configuration for an interface named obr0
  3. 3. OpenVSwitch related configuration
  4. 4. Summary

Post Title Image

Note This post is a follow up on my post OpenVSwitch: Multi-Host Overlay Network.
The interface in this example is named br0. Change according to your interface.

Preparing for using the interface configurations

To persist the configurations you can either use the NetworkManager or use good old network-scripts.
Here I’m going to show how it’s done using the good old network-scripts.
First at all we have to disable the NetworkManager service with this command:

systemctl disable NetworkManager.service

And enable the old fashioned network.service with:

systemctl enable network.service

Warning You need to have properly configured network-scripts for your other “normal” interfaces too (like enp3s0) or else after a reboot the network connectivity to your server will not work correctly!!

We can now go on to creating the configuration for the OpenVSwitch bridges and ports.

Creating configuration for an interface named obr0

Note You should only need to persist IP configurations for bridge devices and not ports.

Create a file called /etc/sysconfig/network-scripts/ifcfg-obr0:

NAME="obr0"
DEVICE="obr0"
NM_CONTROLLED="yes"
ONBOOT="yes"
IPV6INIT=no
TYPE="OVSBridge"
DEVICETYPE="ovs"
MTU=1400
IPADDR=10.244.1.0
PREFIX=16

What does what do

  • NAME="YOUR_INTERFACE_NAME" - The name of the interface.
  • DEVICE="YOUR_DEVICE_NAME" - The name of the interface.
  • NM_CONTROLLED="yes" - The name of the interface.
  • ONBOOT="INTERFACE_NAME" - If yes, the interface is created when the server boots. Should be yes in most cases.
  • IPV6INIT="INTERFACE_NAME" - The name of the interface.
  • TYPE="OVSBridge" - The type of the interface (see OpenVSwitch related configuration for more info)
  • DEVICETYPE="ovs" - The device type of the interface (see OpenVSwitch related configuration for more info).
  • MTU=YOUR_MTU - The MTU of the interface (Only add this option if you know what you are doing).
  • IPADDR=YOUR_INTERFACE_IP_ADDRESS - The name of the created interface.
  • PREFIX=YOUR_NETWORK_PREFIX - The name of the created interface.

OpenVSwitch related configuration

The following options/arguments are important when configuring OpenVSwitch created interfaces:

Summary

That’s all you need to do, disable the NetworkManager.service and activate the good old network service.