2019 SDN上机第1次作业

1. 安装轻量级网络仿真工具Mininet

1.先安装git

2.clone下来mininet

3.安装mininet

4.安装成功

2. 用字符命令搭建如下拓扑，要求写出命令

1.线型（Linear）拓扑，交换机数=主机数=3

2.树型（tree）拓扑，扇出为3，深度为2

3. 利用可视化工具搭建如下拓扑，并要求支持OpenFlow 1.0 1.1 1.2 1.3，设置h1（10.0.0.10）、h2（10.0.0.11）、h3（10.0.0.12），拓扑搭建完成后使用命令验证主机ip，查看拓扑端口连接情况。

设置支持openflow 1.0,1.1,1.2,1.3

miniedit构建网络并设置主机ip

命令行验证

4. 利用Python脚本完成如下图所示的一个Fat-tree型的拓扑（交换机和主机名需与图中一致，即s1_s6，h1h8，并且链路正确，请给出Mininet相关截图）

python代码截图：

命令行效果

PS：

python源代码：

#!/usr/bin/python

"""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
    c = []
    a = []
    e = []
      
    # add core ovs  
    for i in range( L1 ):
            sw = self.addSwitch( 's{}'.format( i + 1 ) )
            c.append( sw )

    # add aggregation ovs
    for i in range( L2 ):
            sw = self.addSwitch( 's{}'.format( L1 + i + 1 ) )
            a.append( sw )

    # add edge ovs
 
    # 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
 
    #add hosts and its links with edge ovs
    count = 1
    for sw1 in a:
            for i in range(2):
                host = self.addHost( 'h{}'.format( count ) )
                self.addLink( sw1, host )
                count += 1

topos = { 'mytopo': ( lambda: MyTopo() ) }