实验2_Open vSwitch虚拟交换机实践

1.基础要求

a) /home/用户名/学号/lab2/目录下执行ovs-vsctl show命令截图

p0和p1连通性测试的执行结果截图

b) /home/用户名/学号/lab2/目录下开启Mininet CLI并执行pingall命令的截图、上述目录下查看OVS流表的命令结果截图，wireshark抓包截图

pingall

ovs流表

wireshark

2.进阶要求

python代码

!/usr/bin/python

from mininet.node import CPULimitedHost, Host, Node
from mininet.node import OVSKernelSwitch, UserSwitch
from mininet.net import Mininet
from mininet.node import Controller, RemoteController, OVSController
from mininet.node import IVSSwitch
from mininet.cli import CLI
from mininet.log import setLogLevel, info
from mininet.link import TCLink, Intf
from subprocess import call

def myNet():

net = Mininet( topo=None,
               build=False,
               ipBase='10.0.0.0/8')

info( '*** Adding controller\n' )
c0=net.addController(name='c0',
                  controller=Controller,
                  ip='127.0.0.1',
                  protocol='OpenFlow13',
                  port=6653)

info( '*** Add hosts\n')
h1 = net.addHost('h1', cls=Host, ip='10.0.0.1', defaultRoute=None)
h2 = net.addHost('h2', cls=Host, ip='10.0.0.2', defaultRoute=None)
h3 = net.addHost('h3', cls=Host, ip='10.0.0.3', defaultRoute=None)
h4 = net.addHost('h4', cls=Host, ip='10.0.0.4', defaultRoute=None)

info( '*** Add switches\n')
s1 = net.addSwitch('s1', cls=OVSKernelSwitch)
s2 = net.addSwitch('s2', cls=OVSKernelSwitch)

info( '*** Add links\n')
net.addLink(h1, s1, 1, 1)
net.addLink(h2, s1, 1, 2)
net.addLink(h3, s2, 1, 1)
net.addLink(h4, s2, 1, 2)
net.addLink(s1, s2, 3, 3)

info( '*** Starting network\n')
net.build()

info( '*** Starting controllers\n')
for controller in net.controllers:
    controller.start()

info( '*** Starting switches\n')
net.get('s1').start([c0])
net.get('s2').start([c0])

info( '*** Post configure switches and hosts\n')
s1.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s1 priority=1,in_port=1,actions=push_vlan:0x8100,set_field:4096-\>vlan_vid,output:3')
s1.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s1 priority=1,in_port=2,actions=push_vlan:0x8100,set_field:4097-\>vlan_vid,output:3')
s1.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s1 priority=1,dl_vlan=0,actions=pop_vlan,output:1')
s1.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s1 priority=1,dl_vlan=1,actions=pop_vlan,output:2')

s2.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s2 priority=1,in_port=1,actions=push_vlan:0x8100,set_field:4096-\>vlan_vid,output:3')
s2.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s2 priority=1,in_port=2,actions=push_vlan:0x8100,set_field:4097-\>vlan_vid,output:3')
s2.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s2 priority=1,dl_vlan=0,actions=pop_vlan,output:1')
s2.cmd('sudo ovs-ofctl -O OpenFlow13 add-flow s2 priority=1,dl_vlan=1,actions=pop_vlan,output:2')

info( "*** Running test\n" )
h1.cmdPrint( 'ping -c 3 ' + h4.IP() )
h1.cmdPrint( 'ping -c 3 ' + h3.IP() )
h2.cmdPrint( 'ping -c 3 ' + h4.IP() )
h2.cmdPrint( 'ping -c 3 ' + h3.IP() )
h3.cmdPrint( 'ping -c 3 ' + h2.IP() )
h3.cmdPrint( 'ping -c 3 ' + h1.IP() )
h4.cmdPrint( 'ping -c 3 ' + h2.IP() )
h4.cmdPrint( 'ping -c 3 ' + h1.IP() )

CLI(net)
net.stop()

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

进阶结果

pingall

实验心得

这次实验根据PPT和老师给的链接就可以解决所有问题。

用于在二层交换机上分割广播域的技术，就是VLAN。通过利用VLAN，我们可以自由设计广播域的构成，提高网络设计的自由度。

进阶python代码完成后，运行“sudo python mytopo3.py”前要清空之前拓扑，清空代码“sudo mn -c”。
在给多个交换机下发流表时，通过ping操作测试验证主机间的连通性，并通过-Q参数设置不同的tos值验证主机间的连通性及到达目的地址的时间。