Open vSwitch虚拟交换机实践

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



进阶要求:




点击查看代码
#!/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()

个人总结:
本次实验有用到上一次构建拓扑的的方法,主要先构建一个拓扑结构,然后使用了新的ovs交换机,将原本全通的链路进行阻断,这其中在一开始顺序搞错了,创建好全通的拓扑以后没有添加流表就继续pingall了以为出错,又重新检查代码,在添加好流表以后,成功阻断,实现了实验要求的h1和h3,h2和h4的连通。然后下载没用过的抓包软件还是比较顺利,要注意的是,将wireshark软件打开后,需要重回mininet,pingall一下,这时wireshark将会对选择的s1进行抓包。在进阶实验中,根据参考实验写好代码以后需要将之前构建的拓扑结构删除,不然端口会一直被占用,使用sudo mn -c进行删除

posted @ 2022-09-24 23:02  212002125王昊  阅读(14)  评论(0编辑  收藏  举报