1. 在需要配置文件之前，需要安装相应软件，hostapd提供AP服务 , isc-dhcp-server网络配置
tip: 配置文件放在txt文本中，需要去除自动换行，复制后会出现问题。
2. Restart network in ubuntu, use "ifdown" and "ifup", Eg: ifdown wlan0; Restart hostapd in ubuntu, "sudo service hostapd restart";
3. 恢复ubuntu自带文件，如果已经对已有配置文件做出修改
(1) Find out what package installed the config file:
$ dpkg -S unity-greeter.conf
unity-greeter: /etc/lightdm/unity-greeter.conf(2) Rename (or delete) the config file you wish to restore:
sudo mv -i /etc/lightdm/unity-greeter.conf /etc/lightdm/unity-greeter.conf.bak (3) Run the following command, replacing <package-name> with the name of the package:
sudo apt-get -o Dpkg::Options::="--force-confmiss" install --reinstall <package-name>(4) If everything worked as expected, you should get this message:
Configuration file `/etc/lightdm/unity-greeter.conf', does not exist on system.
Installing new config file as you requested.4. ifconfig 查看网络的interface, iwconfig 查看硬件, reboot重启系统, ping+地址 查看网速；其中iwconfig mode为master就代表成功
5. iperf使用： 首先安装 sudo apt-get install iperf. 然后利用man iperf查阅使用说明. Eg: Assuming the address of server is 10.0.1.1, then in server, iperf -s. In client, iperf -c 10.0.1.1