实验2：Open vSwitch虚拟交换机实践

实验报告

基础提交

1.（1）/home/用户名/学号/lab2/目录下执行ovs-vsctl show命令执行结果截图

1.（2）p0和p1连通性测试的执行结果截图

2.(1) /home/用户名/学号/lab2/目录下开启Mininet CLI并执行pingall命令的截图

2.（2） 上述目录下查看OVS流表的命令结果截图

配置流表项

查看流表项

pingall 截图

2.（3） wireshark抓包截图

进阶要求

代码

#!/usr/bin/env python

from mininet.net import Mininet
from mininet.node import Controller, RemoteController, OVSController
from mininet.node import CPULimitedHost, Host, Node
from mininet.node import OVSKernelSwitch, UserSwitch
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 myNetwork():

    net = Mininet( topo=None,
                   build=False,
                   ipBase='10.0.0.1/24')

    info( '*** Adding controller\n' )
    c0=net.addController(name='c0',
                      controller=Controller,
                      protocol='tcp',
                      port=6633)

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

    info( '*** Add hosts\n')
    h1 = net.addHost('h1', cls=Host, ip='10.0.0.1/24', defaultRoute=None)
    h2 = net.addHost('h2', cls=Host, ip='10.0.0.2/24', defaultRoute=None)
    h3 = net.addHost('h3', cls=Host, ip='10.0.0.3/24', defaultRoute=None)
    h4 = net.addHost('h4', cls=Host, ip='10.0.0.4/24', defaultRoute=None)

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

    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')

    CLI(net)
    net.stop()

if __name__ == '__main__':
    setLogLevel( 'info' )
    myNetwork()

执行结果截图

个人总结

1.在添加流表时显示ovs-ofctl: s1 is not a bridge or a socket错误，后发现添加的流表的同时需要mininet在后台同时运行才行。添加流表的时候要注意O和0的区别，命令太多，要仔细输入。
2.抓包的时候要在mininet同时进行h1 ping h3 或 h2 ping h4。
3.这一次有做进阶要求，借鉴基础实验里面的python代码，在其基础上添加流表项，再次运行，进行抓包，得到一样的结果！
4.总体上，这次的实验难度不大，过程还是蛮顺利的。