实验2:Open vSwitch虚拟交换机实践

1.基础要求提交

a)

(1)/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)

(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)上述目录下查看OVS流表的命令结果截图

(3)wireshark抓包截图


2.进阶要求

使用Mininet,编写Python代码,生成(一)中的SDN拓扑,并在代码中直接使用OVS命令,做到可以直接运行Python程序完成和(一)相同的VLAN划分。

点击查看代码

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='10.0.0.1/24')

    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()



![](https://img2022.cnblogs.com/blog/2972371/202209/2972371-20220921144328404-653266322.png)

3.总结

个人认为这次是实验还是很难的,为什么这么说。是因为对命令什么的都不懂,流表也只知道只有什么作用而不知道怎么改,敲多了代码还是熟练了起来。

但是在了解端口概念后便是茅塞顿开,当然还不是十分了解。所以进阶任务只能后面再补了。

而且为什么我的抓包是乱码,很奇怪的,其他都没错,只能去问问老师与同学了。

透过这次测试技术的实验,使我学到了不少实用的知识,更重要的是,做实验的过程,思考问题的方法,这与做其他的实验是通用的,真正使我们受益匪浅。

posted @ 2022-09-20 22:58  念烨  阅读(11)  评论(0编辑  收藏  举报