实验1:SDN拓扑实践
一、实验目的
- 能够使用源码安装Mininet;
- 能够使用Mininet的可视化工具生成拓扑;
- 能够使用Mininet的命令行生成特定拓扑;
- 能够使用Mininet交互界面管理SDN拓扑;
- 能够使用Python脚本构建SDN拓扑。
二、实验环境
Ubuntu 20.04 Desktop amd64
三、实验要求
(一)基本要求
- a) 第1步Mininet运行结果截图
- b) 第2步的执行结果截图
- c) 第3步提交修改过的“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')
s2 = net.addSwitch('s2', cls=OVSKernelSwitch)
s1 = net.addSwitch('s1', cls=OVSKernelSwitch)
info( '*** Add hosts\n')
h1 = net.addHost('h1', cls=Host, ip='10.0.0.1', defaultRoute=None,cpu=0.5)
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)
h3 = net.addHost('h3', cls=Host, ip='10.0.0.3', defaultRoute=None)
info( '*** Add links\n')
net.addLink(h1, s1,bw=10,delay='5ms',max_queue_size=1000,loss=50)
net.addLink(h2, s1)
net.addLink(s1, s2)
net.addLink(h3, s2)
net.addLink(s2, h4)
info( '*** Starting network\n')
net.build()
info( '*** Starting controllers\n')
for controller in net.controllers:
controller.start()
info( '*** Starting switches\n')
net.get('s2').start([c0])
net.get('s1').start([c0])
info( '*** Post configure switches and hosts\n')
CLI(net)
net.stop()
if __name__ == '__main__':
setLogLevel( 'info' )
myNetwork()
(二)进阶要求
编写.py拓扑文件,命名为“学号_fattree.py”;
#!/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[int(i/2)::int(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( L2 ):
for sw1 in a[i:i+2]:
for sw2 in e[i*2:(i+2)*2]:
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() ) }
Mininet运行结果
四、个人总结
本次实验为软件定义网络的第一次实践。主要任务是搭建Mininet实验环境以及动手尝试通过不同的方式搭建简单的的网络拓扑结构。在学习过程中也有遇到一些问题,如可视化网络拓扑保存下来的文件是加密文件,经过询问同学以及上网搜索,最终直接修改权限后修改了网络性能限制。
本次实验了解并能够使用多种方法构建了网络拓扑:Mininet可视化工具、在命令行使用Python脚本。Mininet可视化工具最简单,编写Python脚本更适用于复杂的网络。这个实验让我了解了如何构建网络拓扑,实验总体还是比较容易上手,对于进阶内容参考资料发挥作用更大,在今后还是要多学习Python的相关知识,以便于更好解决SDN的问题,对于SDN也还有很多需要学习和思考的地方。
标签:info,Mininet,mininet,拓扑,实践,self,import,SDN,net From: https://www.cnblogs.com/Jue1108/p/16709274.html