What is Open vSwitch?
Open vSwitch is a production quality, multilayer virtual switch licensed under the open source Apache 2.0 license. It is designed to enable massive network automation through programmatic extension, while still supporting standard management interfaces and protocols (e.g. NetFlow, sFlow, IPFIX, RSPAN, CLI, LACP, 802.1ag). In addition, it is designed to support distribution across multiple physical servers similar to VMware‘s vNetwork distributed vswitch or Cisco‘s Nexus 1000V. See full feature list here
1.安装依赖软件包，及创建普通用户ovs。
yum -y install wget gcc make python-devel openssl-devel kernel-devel graphviz kernel-debug-devel autoconf automake rpm-build redhat-rpm-config libtool
adduser ovs
su - ovs
2.下载源码包，并创建rpm包。
mkdir -p ~/rpmbuild/SOURCES
wget http://openvswitch.org/releases/openvswitch-2.3.2.tar.gz
cp openvswitch-2.3.2.tar.gz ~/rpmbuild/SOURCES/
tar xfz openvswitch-2.3.2.tar.gz
sed ‘s/openvswitch-kmod, //g‘ openvswitch-2.3.2/rhel/openvswitch.spec > openvswitch-2.3.2/rhel/openvswitch_no_kmod.spec
rpmbuild -bb --nocheck openvswitch-2.3.2/rhel/openvswitch_no_kmod.spec
exit
3.创建ovs配置目录，并安装制作好的rpm包。
mkdir /etc/openvswitch
yum localinstall /home/ovs/rpmbuild/RPMS/x86_64/openvswitch-2.3.2-1.x86_64.rpm
4.如果selinux开启，请执行如下操作，如未开启，请略过此步骤。
yum install policycoreutils-python
semanage fcontext -a -t openvswitch_rw_t "/etc/openvswitch(/.*)?"
restorecon -Rv /etc/openvswitch
5.启动服务，并查看ovs版本信息。
chkconfig openvswitch on
ovs-vsctl -V
参考文档：
博客：https://n40lab.wordpress.com/2015/06/28/centos-7-installing-openvswitch-2-3-2-lts/
官方文档：http://openvswitch.org/