实验2：Open vSwitch虚拟交换机实践

实验2：Open vSwitch虚拟交换机实践

一、基本要求

1./home/用户名/学号/lab2/目录下执行ovs-vsctl show命令

p0和p1连通性测试的执行结果截图

2./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

二、进阶要求

代码

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='10.0.0.0/8')

    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', 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 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')

    info( '*** dump flows\n')
    print(s1.cmd('sudo ovs-ofctl -O OpenFlow13 dump-flows s1'))
    print(s2.cmd('sudo ovs-ofctl -O OpenFlow13 dump-flows s2'))

    info( "*** Running test\n" )
    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() )
    CLI(net)
    net.stop()

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

运行截图

三、个人总结

1. 本次实验难度适中，通过阅读PDF文档基本上都能顺利完成
2. 由于实验PDF在ovs-vsctl基础操作要求中p0和p1端口ip地址有误，导致在测试时显示网络不可达，经过理论学习，把p0端口ip地址改为192.168.0.100就解决这一问题。
3. 使用wireshark抓包时应该另开一个终端。
4. 通过本次的实验，我掌握了ovs-vsctl相关基本操作，学会运用Python来运行ovs命令，收获很多，也加深了我对SDN的理解，