初试mininet(可选PyCharm)

0x00 Mininet

尝试理解一下mininet,话说mininet是基于python编写的,代码结构清晰,简直清醒脱俗((≧▽≦)/啦啦啦),附上链接mininet,mark一下。

0x01 Important classes, methods, functions

简单记录一下比较重要的类和方法

Important classes, methods, functions and variables in the above code include:

Topo: the base class for Mininet topologies

build(): The method to override in your topology class. Constructor parameters (n) will be passed through to it automatically by Topo.__init__().

addSwitch(): adds a switch to a topology and returns the switch name

addHost(): adds a host to a topology and returns the host name

addLink(): adds a bidirectional link to a topology (and returns a link key, but this is not important). Links in Mininet are bidirectional unless noted otherwise.

Mininet: main class to create and manage a network

start(): starts your network

pingAll(): tests connectivity by trying to have all nodes ping each other

stop(): stops your network

net.hosts: all the hosts in a network

dumpNodeConnections(): dumps connections to/from a set of nodes.

setLogLevel( 'info' | 'debug' | 'output' ): set Mininet's default output level; 'info' is recommended as it provides useful information.

0x02 Sample

自己写了一个简单的,h1~h5链接到s1, h6~h10链接到s2,然后s1和s2互联 一开始想着SingleSwitchTopo的方法来写LinearTopo,结果一直报错,╮(╯_╰)╭,明明人家代码都写好了 SingleSwitchTopoSingle switch connected to k hosts,而Linear topology of k switches, with n hosts per switch

#!/usr/bin/python

from mininet.topo import Topo
from mininet.net import Mininet
from mininet.util import irange,dumpNodeConnections
from mininet.log import setLogLevel

class LinearTopo(Topo):
    ""
    """Linear topology of k switches, with n hosts per switch."""
    ""
    def __init__(self, k=2, n=5,**opts):

        """k:number of switches (and hosts)"""
        """hconf: host configuration options"""
        """lconf: ling configuration options"""
        super(LinearTopo, self).__init__(**opts)
        self.n = n
        self.k = k
        """creates 2 switchs"""
        switch1 = self.addSwitch('s1')
        switch2 = self.addSwitch('s2')

        """creates h1~h5 and addLink switch1"""

        for i in irange(1,n):
            host = self.addHost('h%s' %i)
            self.addLink(host,switch1)

        """creates h6~h10 and addLink switch2"""

        for i in irange(n+1,n+5):
            host =self.addHost('h%s' %i)
            self.addLink(host,switch2)

        """addLink switch1 and switch2"""
        self.addLink(switch1,switch2)


def simpleTest():
    "Create and test a simple network"
    topo = LinearTopo(k=2,n=5)
    net = Mininet(topo)
    #start the network
    net.start()
    print "Dumping host connections"
    dumpNodeConnections(net.hosts)

    #test the connections of the network
    print "Testing network connectivity"
    net.pingAll()

    #Test the bandwidth of the h* and h*
    print "Testing bandwidth between h1 and h2"
    h1, h2 = net.get('h1', 'h2')
    net.iperf((h1,h2))

    print "Testing bandwidth between h10 and h1"
    h10, h1 = net.get('h10', 'h1')
    net.iperf((h10,h1))


    #stop the network
    net.stop()

if __name__== '__main__':
    # Tell mininet to print useful information
    setLogLevel('info')
    simpleTest()

0x04 run in shell

命令行直接运行

#将代码保存到一个文件中
sudo vi test.py

#运行
sudo python test.py

0x05 Output

*** Creating network
*** Adding controller
*** Adding hosts:
h1 h2 h3 h4 h5 h6 h7 h8 h9 h10 
*** Adding switches:
s1 s2 
*** Adding links:
(h1, s1) (h2, s1) (h3, s1) (h4, s1) (h5, s1) (h6, s2) (h7, s2) (h8, s2) (h9, s2) (h10, s2) (s1, s2) 
*** Configuring hosts
h1 h2 h3 h4 h5 h6 h7 h8 h9 h10 
*** Starting controller
c0 
*** Starting 2 switches
s1 s2 ...
Dumping host connections
h1 h1-eth0:s1-eth1
h2 h2-eth0:s1-eth2
h3 h3-eth0:s1-eth3
h4 h4-eth0:s1-eth4
h5 h5-eth0:s1-eth5
h6 h6-eth0:s2-eth1
h7 h7-eth0:s2-eth2
h8 h8-eth0:s2-eth3
h9 h9-eth0:s2-eth4
h10 h10-eth0:s2-eth5
Testing network connectivity
*** Ping: testing ping reachability
h1 -> h2 h3 h4 h5 h6 h7 h8 h9 h10 
h2 -> h1 h3 h4 h5 h6 h7 h8 h9 h10 
h3 -> h1 h2 h4 h5 h6 h7 h8 h9 h10 
h4 -> h1 h2 h3 h5 h6 h7 h8 h9 h10 
h5 -> h1 h2 h3 h4 h6 h7 h8 h9 h10 
h6 -> h1 h2 h3 h4 h5 h7 h8 h9 h10 
h7 -> h1 h2 h3 h4 h5 h6 h8 h9 h10 
h8 -> h1 h2 h3 h4 h5 h6 h7 h9 h10 
h9 -> h1 h2 h3 h4 h5 h6 h7 h8 h10 
h10 -> h1 h2 h3 h4 h5 h6 h7 h8 h9 
*** Results: 0% dropped (90/90 received)
Testing bandwidth between h1 and h2
*** Iperf: testing TCP bandwidth between h1 and h2 
*** Results: ['35.8 Gbits/sec', '35.8 Gbits/sec']
Testing bandwidth between h10 and h1
*** Iperf: testing TCP bandwidth between h10 and h1 
*** Results: ['36.4 Gbits/sec', '36.4 Gbits/sec']
*** Stopping 1 controllers
c0 
*** Stopping 11 links
...........
*** Stopping 2 switches
s1 s2 
*** Stopping 10 hosts
h1 h2 h3 h4 h5 h6 h7 h8 h9 h10 
*** Done

0x06 Problems

遇到的问题: 一.Mininet只能使用python2使用python3不行,即使用外部库也不行二.PyCharm配置root运行文件 一开始我没有使用shell来运行,而是使用了PyCharm来跑,然后出现了一个问题,就是Mininet must run as a root,即必须以管理员身份进行,所以需要在PyCharm上设置管理员运行,具体做法:

  1. 在/usr/bin/目录下新建文件 python_sudo.sh :
sudo gedit /usr/bin/python_sudo.sh

在文件中写入下列代码:

#! /bin/bash 
sudo python $*
  1. 给sh文件赋予权限:
cd /usr/bin/
sudo chmod a+x python_sudo.sh
  1. 编辑visudo(其他工具有点问题):
sudo visudo
  1. 在最后一行输入,然后保存:
%sudo ALL=NOPASSWD: /usr/bin/python
  1. 将pycharm 中的 File→Settings→Project Interpreter 置换为自己写的python_sudo.sh,在下图选中框右边有个小齿轮,点那个进行Add就OK了
  1. 同理可以对python3等进行设定,只要在将python改成对应版本就可以(前提是在这个目录下已安装)

0x07 Paint

一个能用画图工具

sudo apt-get install kolourpaint4

然后搜paint就OK了

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