目录
1. 安装轻量级网络仿真工具Mininet
环境：Ubuntu 18.04 LTS
（经测试，WSL下无法正常运行）
i.修改源为清华源
vi /etc/apt/sources.list
在最顶部添加
# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
# 预发布软件源，不建议启用
# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
保存并退出
ii. 安装mininet
sudo apt-get install mininet
如果出现了*** No default OpenFlow controller found for default switch! *** Falling back to OVS Bridge
需要安装OpenFlow来解决
iii.安装OpenFlow
git clone git://github.com/mininet/mininet
sudo mininet/util//install.sh -a
2.用字符命令搭建如下拓扑，要求写出命令
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。
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s1s6，h1h8，并且链路正确，请给出Mininet相关截图
