建一个简单的模型，使用一个单交换机，然后链接n个主机形成拓扑，然后对每个链路设置带宽，延迟时间，和丢包率。
这里就选择建一个单交换机和六个主机的作为例子。
创建py脚本生成拓扑：写一个类生成一个单交换机和六个主机的拓扑，并且给每个主机和交换机之间的连接赋予100m的带宽，5ms的延迟和1%的丢包率。然后通过pingall函数测试连接，iperf函数测试主机间的带宽，
1 from mininet.topo import Topo
2 from mininet.net import Mininet
3 from mininet.node import CPULimitedHost
4 from mininet.link import TCLink
5 from mininet.util import dumpNodeConnections
6 from mininet.log import setLogLevel
7
8
9 class SingleSwitchTopo(Topo):
10 def __init__(self, n=2, **opts):
11 Topo.__init__(self, **opts)
12 switch = self.addSwitch('s1')
13 for h in range(n):
14 # Each host gets 50%/n of system CPU
15 host = self.addHost('h%s' % (h + 1), cpu=.5/n)
16 # 100 Mbps, 5ms delay, 1% Loss, 1000 packet queue
17 self.addLink(host, switch, bw=100, delay='5ms', loss=1,
18 max_queue_size=1000, use_htb=True)
19
20
21 def perfTest():
22 topo = SingleSwitchTopo(n=6)
23 net = Mininet(topo=topo, host=CPULimitedHost, link=TCLink)
24 net.start()
25 print "Dumping host connections"
26 dumpNodeConnections(net.hosts)
27 print "Testing network connectivity"
28 net.pingAll()
29 print "Testing bandwidth between h1 and h4"
30 h1, h4 = net.get('h1', 'h4')
31 net.iperf((h1, h4))
32 print "Testing bandwidth between h1 and h6"
33 h1, h6 = net.get('h1', 'h6')
34 net.iperf((h1, h6))
35 net.stop()
36
37
38 if __name__ == '__main__':
39 setLogLevel('info')
40 perfTest()
ps:如果直接执行出现错误找不到py解释器的话，在代码开头加上#!/usr/bin/python。或者直接使用
1 sudo python 文件名.py
执行
结果如下图所示：
瞎搞一波，再试试两个交换机相互连接，然后分别下挂三个主机。link全部赋予10m带宽，5ms延迟和0%的丢包率。
1 from mininet.topo import Topo
2 from mininet.net import Mininet
3 from mininet.node import CPULimitedHost
4 from mininet.link import TCLink
5 from mininet.util import dumpNodeConnections
6 from mininet.log import setLogLevel
7
8
9 class DoubleSwitchTopo(Topo):
10 def __init__(self, n=2, **opts):
11 Topo.__init__(self, **opts)
12 switch1 = self.addSwitch('s1')
13 switch2 = self.addSwitch("s2")
14 self.addLink(switch1, switch2, bw=10, delay='5ms',
15 loss=0, max_queue_size=1000, use_htb=True)
16 for h in range(n/2):
17 host = self.addHost('h%s' % (h + 1), cpu=.5/n)
18 self.addLink(host, switch1, bw=10, delay='5ms', loss=0,
19 max_queue_size=1000, use_htb=True)
20 for h in range(n/2, n):
21 host = self.addHost('h%s' % (h + 1), cpu=.5/n)
22 self.addLink(host, switch2, bw=10, delay='5ms', loss=0,
23 max_queue_size=1000, use_htb=True)
24
25
26 def perfTest():
27 topo = DoubleSwitchTopo(n=6)
28 net = Mininet(topo=topo, host=CPULimitedHost, link=TCLink)
29 net.start()
30 print "Dumping host connections"
31 dumpNodeConnections(net.hosts)
32 print "Testing network connectivity"
33 net.pingAll()
34 print "Testing bandwidth between h1 and h3"
35 h1, h3 = net.get('h1', 'h3')
36 net.iperf((h1, h3))
37 print "Testing bandwidth between h4 and h6"
38 h4, h6 = net.get('h4', 'h6')
39 net.iperf((h4, h6))
40 net.stop()
41
42
43 if __name__ == '__main__':
44 setLogLevel('info')
45 perfTest()
结果如下图：
来源：oschina
链接：https://my.oschina.net/u/4361193/blog/4301725