一、基本要求

a) Mininet运行结果截图

b) 2的执行结果截图

3台交换机，每个交换机连接1台主机，3台交换机连接成一条线。

3台主机，每个主机都连接到同1台交换机上。

c) 3修改过的“学号.py”代码、Mininet运行结果

#!/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='10.0.0.0/8')

    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)
    h3 = net.addHost('h3', cls=Host, ip='10.0.0.3', defaultRoute=None)
    h2 = net.addHost('h2', cls=Host, ip='10.0.0.2', defaultRoute=None)
    h4 = net.addHost('h4', cls=Host, ip='10.0.0.4', defaultRoute=None)

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

    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')

    CLI(net)
    net.stop()

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

二、进阶要求

#!/usr/bin/python
#创建网络拓扑
"""Custom topology example
Adding the 'topos' dict with a key/value pair to generate our newly defined
topology enables one to pass in '--topo=mytopo' from the command line.
"""
 
from mininet.topo import Topo
from mininet.net import Mininet
from mininet.node import RemoteController,CPULimitedHost
from mininet.link import TCLink
from mininet.util import dumpNodeConnections
 
class MyTopo( Topo ):
    "Simple topology example."
 
    def __init__( self ):
        "Create custom topo."
 
        # Initialize topology
        Topo.__init__( self )
        L1 = 2
        L2 = L1 * 2 
        L3 = L2 * 2
        c = []
        a = []
        e = []
          
        # add core ovs  
        for i in range( L1 ):
                sw = self.addSwitch( 'c{}'.format( i + 1 ) )
                c.append( sw )
    
        # add aggregation ovs
        for i in range( L2 ):
                sw = self.addSwitch( 'a{}'.format( L1 + i + 1 ) )
                a.append( sw )
    
        # add edge ovs
        for i in range( L3 ):
                sw = self.addSwitch( 'e{}'.format( L1 + L2 + i + 1 ) )
                e.append( sw )
 
        # add links between core and aggregation ovs
        for i in range( L1 ):
                sw1 = c[i]
                for sw2 in a[i//2::L1//2]:
                # self.addLink(sw2, sw1, bw=10, delay='5ms', loss=10, max_queue_size=1000, use_htb=True)
			            self.addLink( sw2, sw1 )
 
        # add links between aggregation and edge ovs
        for i in range( 0, L2, 2 ):
                for sw1 in a[i:i+2]:
	                for sw2 in e[i*2:i*2+4]:
			            self.addLink( sw2, sw1 )
 
        #add hosts and its links with edge ovs
        count = 1
        for sw1 in e:
                for i in range(2):
                	host = self.addHost( 'h{}'.format( count ) )
                	self.addLink( sw1, host )
                	count += 1
topos = { 'mytopo': ( lambda: MyTopo() ) }

三、个人总结

a)实验难度

按照文档步骤一步一步地完成，感觉本次实验的难度不是很大。文档内容详实，并且附上了相关链接。除个别内容还需自己进一步消化理解并解决。

b)实验过程遇到的困难及解决办法

在基础要求部分：初次接触可视化建立拓扑，查找相关资料，得以正确建立；交互界面管理SDN拓扑时，对相关命令和参数不了解，仔细阅读文档并参考同学作业得以解决；使用python脚本构建SDN拓扑时，要注意python版本。
在进阶部分，一方面按照文档中提供的链接，另一方面之前有接触过python，顺利完成。

c)个人感想

通过本次实验，了解了可视化建立拓扑，能够使用Mininet交互界面管理拓扑，使用Python脚本构建SDN拓扑，提高了解决问题的能力。感谢老师详实的资料与同学们的帮助，也感受到自己的不足，有很多不懂的东西需要不断去学习。

标签：info,mininet,addLink,拓扑,实践,self,import,SDN,net
来源： https://www.cnblogs.com/102299215wxm/p/16692606.html