OpenVSwitch

This document describes how to configure an OpenVSwitch in Alpine Linux.

Installing OVS

apk add openvswitch
rc-update add ovs-modules
rc-update add ovsdb-server
rc-update add ovs-vswitchd
rc-service ovs-modules start
rc-service ovsdb-server start
rc-service ovs-vswitchd start

Using ovs-vsctl

Open VSwithes are manually managed with the ovs-vsctl command.

To manually create a switch named "lan":

ovs-vsctl add-br lan

To add interface eth0 to the switch "lan":

ovs-vsctl add-port lan eth0

Note that you need to set the link status to up on the added interfaces.

ip link set dev eth0 up

Configuration file

configured in /etc/network/interfaces

auto eth0 lan
iface eth0 inet manual
 up ifconfig eth0 0.0.0.0 up
 down ifconfig eth0 down

iface lan inet dhcp

OVS and qemu

Helper scripts

ovs-ifup-lan

#!/bin/sh
switch="lan"
/sbin/ifconfig $1 0.0.0.0 up
ovs-vsctl add-port ${switch} $1
logger "qemu: $1 added to ${switch} at startup of VM"

ovs-ifdown-lan

#!/bin/sh
switch="lan"
/sbin/ifconfig $1 0.0.0.0 down
ovs-vsctl del-port ${switch} $1
logger "qemu: $1 removed from ${switch} at shutdown of VM"

Caveats

Beware to have OVS package files available with no hassle at next reboot! this ca be a problem when running from ram with no cache...