目录
一、基础要求提交
a1) /home/用户名/学号/lab2/目录下执行ovs-vsctl show命令
a2）p0和p1连通性测试的执行结果截图
b1）/home/用户名/学号/lab2/目录下开启Mininet CLI并执行pingall命令的截图
b2）上述目录下查看OVS流表的命令结果截图
b3）wireshark抓包截图
二、进阶要求
阅读SDNLAB实验使用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。
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()
运行结果
三、心得体会
本次实验初步学习了Openflow协议、OVS命令的使用、VLAN、流表等计算机网络的概念等等，也更熟练掌握了miniedit创建拓扑和Python代码的编写。虽然操作部分并不难，完成的过程较为顺利，但是对于细节部分还是一知半解。第一次使用wireshark来抓包，也遇到了一些问题，例如不知道需要pingall之后才能抓包成功，抓包之后生成的东西也不知道是什么意思。但是后来多通过查阅资料和同学的帮助解决了。相信在今后的使用中会越来越熟练。
