GitHub访问加速

由于某些原因，国内访问Github会异常缓慢，在clone仓库时甚至只有10k以下的速度，下载半天有时还会失败需要从头再来，甚是让人恼火。

本文介绍通过修改系统hosts文件的办法，绕过国内DNS解析，直接访问GitHub的CDN节点，从而达到加速的目的。不需要科学上网，也不需要海外的服务器辅助。

1. 获取GitHub官方CDN地址
   打开https://www.ip138.com/
   查询以下三个链接的DNS解析地址
   github.com
assets-cdn.github.com
github.global.ssl.fastly.net
   记录下查询到的IP地址。

2. 修改系统Hosts文件
   打开系统hosts文件(需管理员权限)。
   路径：C:\Windows\System32\drivers\etc
   在末尾添加三行记录并保存。(需管理员权限，注意IP地址与域名间需留有空格)

# 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. 刷新系统DNS缓存
   Windows+X 打开系统命令行（管理员身份）或powershell
   运行 ipconfig /flushdns 手动刷新系统DNS缓存。
   现在打开Github，clone一个项目到本地试试吧，宽带会轻松达到10M/s的速度。