连不上GitHub，也ping不通，亲测解决方案

1.打开hosts文件，C:\Windows\System32\drivers\etc

2.在最后一行添加如下地址

192.30.253.113 github.com
192.30.252.131 github.com
185.31.16.185 github.global.ssl.fastly.net
74.125.237.1 dl-ssl.google.com
173.194.127.200 groups.google.com
192.30.252.131 github.com
185.31.16.185 github.global.ssl.fastly.net
74.125.128.95 ajax.googleapis.com