实验 4：Open vSwitch 实验——Mininet 中使用 OVS 命令

实验要求

1. 学习 ovsSingleBr.py 和 ovsMultiBr.py，在下图拓扑中实现一个 VLAN。

上述代码将 h0 和 h2 划分在 VLAN 0 中，h1 和 h3 划分在 VLAN 1 中，由于拓扑没
有控制器，并且初始化时删除了交换机中的所有流表，因此除非下发流表，否则
主机之间网络无法连通。请尝试修改代码，利用 ovs 命令直接下发 VLAN 设置的
流表项，最终测试 h0 和 h2 互通，h1 和 h3 互通，其余主机均不通，结果如下图。
OVS 实现 VLAN 。

可参考博客：https://www.cnblogs.com/fjlinww/p/11791846.html

创建 111.py 脚本并运行

111.py对应拓扑如下图：

实验内容

修改代码，利用 ovs 命令直接下发 VLAN 设置的流表项，最终测试 h0 和 h2 互通，h1 和 h3 互通，其余主机均不通

代码如下：

、、、

!/usr/bin/python

from mininet.net import Mininet
from mininet.node import Node
from mininet.link import TCLink
from mininet.log import setLogLevel, info

def myNet():
"Create network from scratch using Open vSwitch."

info( "*** Creating nodes
" )
switch0 = Node( 's0', inNamespace=False )
switch1 = Node( 's1', inNamespace=False )
h0 = Node( 'h0' )
h1 = Node( 'h1' )
h2 = Node( 'h2' )
h3 = Node( 'h3' )

info( "*** Creating links
" )
linkopts0=dict(bw=100, delay='1ms', loss=0)
linkopts1=dict(bw=1, delay='100ms', loss=0)
linkopts2=dict(bw=10, delay='50ms', loss=0)
TCLink( switch0, switch1, **linkopts0)
TCLink( h0, switch0, **linkopts1)
TCLink( h2, switch1, **linkopts1)
TCLink( h1, switch0, **linkopts2)
TCLink( h3, switch1, **linkopts2)	

info( "*** Configuring hosts
" )
h0.setIP( '192.168.123.1/24' )
h1.setIP( '192.168.123.2/24' )
h2.setIP( '192.168.123.3/24' )
h3.setIP( '192.168.123.4/24' )
info( str( h0 ) + '
' )
info( str( h1 ) + '
' )
info( str( h2 ) + '
' )
info( str( h3 ) + '
' )
   
info( "*** Starting network using Open vSwitch
" )
switch0.cmd( 'ovs-vsctl del-br dp0' )
switch0.cmd( 'ovs-vsctl add-br dp0' )
switch1.cmd( 'ovs-vsctl del-br dp1' )
switch1.cmd( 'ovs-vsctl add-br dp1' )

for intf in switch0.intfs.values():
    print (intf)
    print (switch0.cmd( 'ovs-vsctl add-port dp0 %s' % intf ))

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

print (switch0.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,in_port=1,actions=push_vlan:0x8100,set_field:4096->vlan_vid,output:3' ))
print (switch0.cmd(r'ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,in_port=2,actions=push_vlan:0x8100,set_field:4097->vlan_vid,output:3' ))
print (switch0.cmd(r'sudo ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,dl_vlan=0,actions=pop_vlan,output:1' ))
print (switch0.cmd(r'sudo ovs-ofctl -O OpenFlow13 add-flow dp0 priority=1,dl_vlan=1,actions=pop_vlan,output:2' ))

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' ))

#switch0.cmd('tcpdump -i s0-eth0 -U -w aaa &')
#h0.cmd('tcpdump -i h0-eth0 -U -w aaa &')
info( "*** Running test
" )
h0.cmdPrint( 'ping -Q 0x10 -c 3 ' + h1.IP() )
h0.cmdPrint( 'ping -Q 0x20 -c 3 ' + h2.IP() )
h0.cmdPrint( 'ping -Q 0x30 -c 3 ' + h3.IP() )
h1.cmdPrint( 'ping -Q 0x40 -c 3 ' + h2.IP() )
h1.cmdPrint( 'ping -Q 0x50 -c 3 ' + h3.IP() )
h2.cmdPrint( 'ping -Q 0x60 -c 3 ' + h3.IP() )
#h1.cmdPrint('iperf -s -p 12345 -u &')
#h0.cmdPrint('iperf -c ' + h1.IP() +' -u -b 10m -p 12345 -t 10 -i 1')

info( "*** Stopping network
" )
switch0.cmd( 'ovs-vsctl del-br dp0' )
switch0.deleteIntfs()
switch1.cmd( 'ovs-vsctl del-br dp1' )
switch1.deleteIntfs()
info( '
' )

if name == 'main':
setLogLevel( 'info' )
info( '*** Scratch network demo (kernel datapath) ' )
Mininet.init()
myNet()
、、、

执行该文件，结果如下：