2019 SDN上机第一次作业

1. 安装轻量级网络仿真工具Mininet

使用github上的Mininet源安装，使用命令依次为：

git clone https://github.com/mininet/mininet.git
cd mininet/util
./install.sh

安装成功终端显示Enjoy Mininet

2. 用字符命令搭建如下拓扑，要求写出命令

 sudo mn --topo linear,4

查看net信息 输入命令net

查看所有节点连通性 输入命令pingall

创建树形拓扑

sudo mn --topo tree,depth=3,fanout=2

查看net信息 输入命令net

查看所有节点连通性 输入命令pingall

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。

在配置完后，执行run，终端产生拓扑信息，同时展示网络信息和测试连通性

验证主机ip，查看拓扑端口连接情况

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脚本代码

#!/usr/bin/python
# sudo mn --custom fattree.py --topo mytopo --switch ovsk,protocols=OpenFlow10
"""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 = 4
        c = []
        a = []
          
        # 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 links between core and aggregation ovs
        for i in range(L1):
                sw1 = c[i]
                for sw2 in a[0: :1]:
                    self.addLink(sw2, sw1)
 
        #add hosts and its links with aggregation 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())}

命令行输入sudo mn --custom fattree.py --topo mytopo --switch ovsk,protocols=OpenFlow10

mininet截图