Ubuntu14.04 solution to slow wireless network

Windows and ubuntu systems have always been used. Currently, Windows 7 + ubuntu14.04 are used. It is easier to work in windows. But sometimes you have to go to linux for installation. Haha. Let's talk about how to handle the problem of slow wireless network in ubuntu14.04.
1. First, it seems that starting from ubuntu12.04, the default dns server of the system is 127.0.0.1. In addition, after the configuration file/etc/reslov. conf modifies the specified dns server, the system restarts and becomes invalid. The configuration file/etc/resolvconf/resolv. conf. d/head is permanently modified.
2. Then, the terminal executes the following modifications. To solve the problem of slow wireless Internet access in ubuntu. If wireless wifi is not enabled (the network icon in the upper left corner-> enable-Wi-Fi is checked:

Sudo ifconfig wlan0 down
Sudo rmmod-f ath9k
Sudo modprobe ath9k nohwcrypt = 1
Sudo ifconfig wlan0 up

Enable wireless WIFI.
Previously, the gateway was pinged for about MS or even ms of data. The following figure shows the effect.