实验二：Open vSwitch虚拟交换机实践

一、实验目的

能够对Open vSwitch进行基本操作；
能够通过命令行终端使用OVS命令操作Open vSwitch交换机，管理流表；
能够通过Mininet的Python代码运行OVS命令，控制网络拓扑中的Open vSwitch交换机

二、实验环境

Ubuntu 20.04 Desktop amd64

三、实验内容

1、ovs-vsctl基础操作实践

p0 ping p1

show

2、mininet拓扑

pingall

查看s1和s2流表

wireshark抓包

（二）进阶要求

代码：

from mininet.net import Mininet
from mininet.node import Node
from mininet.link import Link
from mininet.log import setLogLevel, info
def myNet():
"Create network from scratch using Open vSwitch."

info( "*** Creating nodes\n" )
switch1 = Node( 's1', inNamespace=False )
switch2 = Node( 's2', inNamespace=False )
h1 = Node( 'h1' )
h2 = Node( 'h2' )
h3 = Node( 'h3' )
h4 = Node( 'h4' )

info( "*** Creating links\n" )
Link( h1, switch1)
Link( h2, switch1)
Link( h3, switch2)
Link( h4, switch2)
Link( switch1, switch2)

info( "*** Configuring hosts\n" )
h1.setIP( '192.168.123.1/24' )
h2.setIP( '192.168.123.2/24' )
h3.setIP( '192.168.123.3/24' )
h4.setIP( '192.168.123.4/24' )

switch1.cmd( 'ovs-vsctl del-br dp1' )
switch1.cmd( 'ovs-vsctl add-br dp1' )
switch2.cmd( 'ovs-vsctl del-br dp2' )
switch2.cmd( 'ovs-vsctl add-br dp2' )

for intf in switch1.intfs.values():
print (intf)
print (switch1.cmd( 'ovs-vsctl add-port dp1 %s' % intf ))

for intf in switch2.intfs.values():
print (intf)
print (switch2.cmd( 'ovs-vsctl add-port dp2 %s' % intf ))
print (switch1.cmd(r'ovs-vsctl show'))
print (switch2.cmd(r'ovs-vsctl show'))

print (switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,in_port=1,actions=push_vlan:0x8100,set_field:4096-\>vlan_vid,output:3'))
print (switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,in_port=2,actions=push_vlan:0x8100,set_field:4097-\>vlan_vid,output:3'))
print (switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,dl_vlan=0,actions=pop_vlan,output:1'))
print (switch1.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp1 priority=1,dl_vlan=1,actions=pop_vlan,output:2'))

print (switch2.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp2 priority=1,in_port=1,actions=push_vlan:0x8100,set_field:4096-\>vlan_vid,output:3'))
print (switch2.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp2 priority=1,in_port=2,actions=push_vlan:0x8100,set_field:4097-\>vlan_vid,output:3'))
print (switch2.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp2 priority=1,dl_vlan=0,actions=pop_vlan,output:1'))
print (switch2.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp2 priority=1,dl_vlan=1,actions=pop_vlan,output:2'))

h1.cmdPrint( 'ping -c 3 ' + h3.IP() )
h2.cmdPrint( 'ping -c 3 ' + h4.IP() )
h1.cmdPrint( 'ping -c 3 ' + h4.IP() )
h2.cmdPrint( 'ping -c 3 ' + h3.IP() )

info( "*** Stopping network\n" )
switch1.cmd( 'ovs-vsctl del-br dp1' )
switch1.deleteIntfs()
switch2.cmd( 'ovs-vsctl del-br dp2' )
switch2.deleteIntfs()

info( '\n' )

if __name__ == '__main__':
setLogLevel( 'info' )
info( '*** Scratch network demo (kernel datapath)\n' )
Mininet.init()
myNet()