(一)基本要求
使用Mininet可视化工具,生成下图所示的拓扑,并保存拓扑文件名为学号.py。
2.使用Mininet的命令行生成如下拓扑:
a) 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。
b) 3台主机,每个主机都连接到同1台交换机上。
3.在2 b)的基础上,在Mininet交互界面上新增1台主机并且连接到交换机上,再测试新拓扑的连通性。
4.编辑基本要求第1步保存的Python脚本,添加如下网络性能限制,生成拓扑:
a) h1的cpu最高不超过50%;
b) h1和s1之间的链路带宽为10,延迟为5ms,最大队列大小为1000,损耗率50。
#!/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='1.1.1.1', defaultRoute='via 1.1.1.255',cpu=0.5)
h2 = net.addHost('h2', cls=Host, ip='1.1.1.2', defaultRoute='via 1.1.1.255')
h3 = net.addHost('h3', cls=Host, ip='1.1.1.3', defaultRoute='via 1.1.1.255')
h4 = net.addHost('h4', cls=Host, ip='1.1.1.4', defaultRoute='via 1.1.1.255')
info( '*** Add links\n')
net.addLink(h1, s1, bw=10, delay='5ms',max_queue_size=1000, loss=10, use_htb=True)
net.addLink(h2, s1)
net.addLink(s1, s2)
net.addLink(s2, h3)
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('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
编写Python脚本,生成如下数据中心网络拓扑,要求:
编写.py拓扑文件,命名为“学号_fattree.py”;
必须通过Mininet的custom参数载入上述文件,不得直接使用miniedit.py生成的.py文件;
设备名称必须和下图一致;
使用Python的循环功能实现,不得在代码中手工直接添加设备和链路。
#!/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
s = []
# add floor1 ovs
for i in range( L1 + L2 + L3 ):
sw = self.addSwitch( 's{}'.format( i + 1 ) )
s.append( sw )
# add links between core and aggregation ovss
for i in range( L1 ):
sw1 = s[i]
for sw2 in s[L1:L1+L2]:
self.addLink( sw2, sw1 )
# add links between aggregation and edge ovs
for i in range( L1,L1+2 ):
sw1 = s[i]
for sw2 in s[L1 + L2 :L1 + L2 + 4]:
self.addLink( sw2, sw1 )
for i in range( L1+2,L1+L2 ):
sw1 = s[i]
for sw2 in s[L1 + L2 + 4:L1 + L2 + L3]:
self.addLink( sw2, sw1 )
#add hosts and its links with edge ovs
count = 1
for sw1 in s[L1+L2:L1+L2+L3]:
for i in range(2):
host = self.addHost( 'h{}'.format( count ) )
self.addLink( sw1, host )
count += 1
topos = { 'mytopo': ( lambda: MyTopo() ) }
个人总结:
在本次实验中,因为python版本未切换回pytthon2导致没办法运行python代码,在mininet中生成拓扑图,保存格式第一次采用save,导致sudo python 212006113.py不可以打开,按照ppt进行后可顺利打开。
原链路添加主机后要配置ip地址才可以pingall全部通