由于某些原因，國內訪問Github會異常緩慢，在clone倉庫時甚至只有10k以下的速度，下載半天有時還會失敗需要從頭再來，甚是讓人惱火。
本文介紹通過修改系統hosts文件的辦法，繞過國內DNS解析，直接訪問GitHub的CDN節點，從而達到加速的目的。不需要科學上網，也不需要海外的服務器輔助。
1 獲取GitHub官方CDN地址
打開https://www.ipaddress.com/
查詢以下三個鏈接的DNS解析地址
- github.com
- assets-cdn.github.com
- github.global.ssl.fastly.net
記錄下查詢到的IP地址。
2 修改系統Hosts文件
打開系統hosts文件(需管理員權限)。
路徑：C:windowsSystem32driversetc
在末尾添加三行記錄并保存。(需管理員權限，注意IP地址與域名間需留有空格)
# Copyright (c) 1993-2009 Microsoft Corp.
#
# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.
#
# This file contains the mAppings of IP addresses to host names. Each
# entry should be kept on an individual line. The IP address should
# be placed in the first column followed by the corresponding host name.
# The IP address and the host name should be separated by at least one
# space.
#
# Additionally, comments (such as these) may be inserted on individual
# lines or following the machine name denoted by a '#' symbol.
#
# For example:
#
# 102.54.94.97 rhino.acme.com # source server
# 38.25.63.10 x.acme.com # x client host
# localhost name resolution is handled within DNS itself.
# 127.0.0.1 localhost
# ::1 localhost
192.30.253.112 github.com
151.101.72.133 assets-cdn.github.com
151.101.193.194 github.global.ssl.fastly.net
3 刷新系統DNS緩存
Windows+X 打開系統命令行（管理員身份）或powershell
運行 ipconfig /flushdns 手動刷新系統DNS緩存。
現在打開Github，clone一個項目到本地試試吧，作者這電信的寬帶會輕松達到10M/s的速度。
