use the openvswitch tool to setup OVS network for KVM.

use the openvswitch tool to setup OVS network for KVM.

# yum install openvswitch -y
# systemctl start openvswitch.service | #service openvswitch start
# chkconfig openswitch on 


# ovs-vsctl --help
Open vSwitch commands:
  init                        initialize database, if not yet initialized
  show                        print overview of database contents
  emer-reset                  reset configuration to clean state

Bridge commands:
  add-br BRIDGE               create a new bridge named BRIDGE
  add-br BRIDGE PARENT VLAN   create new fake BRIDGE in PARENT on VLAN
  del-br BRIDGE               delete BRIDGE and all of its ports
  list-br                     print the names of all the bridges
  br-exists BRIDGE            exit 2 if BRIDGE does not exist
  br-to-vlan BRIDGE           print the VLAN which BRIDGE is on
  br-to-parent BRIDGE         print the parent of BRIDGE
  br-set-external-id BRIDGE KEY VALUE  set KEY on BRIDGE to VALUE
  br-set-external-id BRIDGE KEY  unset KEY on BRIDGE
  br-get-external-id BRIDGE KEY  print value of KEY on BRIDGE
  br-get-external-id BRIDGE  list key-value pairs on BRIDGE

Port commands (a bond is considered to be a single port):
  list-ports BRIDGE           print the names of all the ports on BRIDGE
  add-port BRIDGE PORT        add network device PORT to BRIDGE
  add-bond BRIDGE PORT IFACE...  add bonded port PORT in BRIDGE from IFACES
  del-port [BRIDGE] PORT      delete PORT (which may be bonded) from BRIDGE
  port-to-br PORT             print name of bridge that contains PORT


# brctl show
# ifconfig switch down
# brctl delif switch eth0
# killall dhclient 
OR:
rhel6# ifconfig switch down; brctl delif switch eth0; brctl delbr switch; service NetworkManager stop
rhel7# ifconfig switch down; brctl delif switch eth0; brctl delbr switch; systemctl disable NetworkManager.service 


# ovs-vsctl add-br ovs0
# ovs-vsctl add-port ovs0 eth0
OR: the above two can in one single line
# ovs-vsctl add-br ovs0 -- add-port ovs0 eth0

# dhclient ovs0
[if bonded: # ovs-vsctl add-bond bond0 eth1 eth2 xxx]


# ovs-vsctl add-port ovs0 tap0
# ovs-vsctl add-port ovs0 tap1 tag=10
# ovs-vsctl add-port ovs0 tap2 tag=20
# ovs-vsctl -- add-port ovs0 vlan10 tag=10 \
-- set interface vlan10 type=internal


Setup guest network up/down script.
# cat /etc/ovs-ifup
#!/bin/sh
switch='ovs0'
/sbin/ifconfig $1 0.0.0.0 up
ovs-vsctl add-port ${switch} $1

#cat /etc/ovs-ifdown
#!/bin/sh
switch='ovs0'
/sbin/ifconfig $1 0.0.0.0 down
ovs-vsctl del-port ${switch} $1


# ovs-vsctl show
5c4e38c9-f83a-4515-9775-fc48e8f5f126
    Bridge "ovs0"
        Port "ovs0"
            Interface "ovs0"
                type: internal
        Port "tap0"
            Interface "tap0"
        Port "eth0"
            Interface "eth0"
    ovs_version: "2.0.1"
# ovs-vsctl del-port tap0
# ovs-vsctl del-br ovs0