在终端依次输入
$ cd /etc
$ su root
$ (输入密码)
$ nano hosts
将下面这段加入hosts文件末尾处
140.82.112.3 github.com
140.82.112.10 nodeload.github.com
140.82.114.6 api.github.com
13.229.189.0 codeload.github.com
185.199.110.133 raw.github.com
185.199.110.153 training.github.com
185.199.110.153 assets-cdn.github.com
185.199.110.153 documentcloud.github.com
185.199.110.154 help.github.com
185.199.110.153 githubstatus.com
199.232.69.194 github.global.ssl.fastly.net
185.199.110.133 raw.githubusercontent.com
185.199.110.133 cloud.githubusercontent.com
185.199.110.133 gist.githubusercontent.com
185.199.110.133 marketplace-screenshots.githubusercontent.com
185.199.110.133 repository-images.githubusercontent.com
185.199.110.133 user-images.githubusercontent.com
185.199.110.133 desktop.githubusercontent.com
185.199.110.133 avatars.githubusercontent.com
185.199.110.133 avatars0.githubusercontent.com
185.199.110.133 avatars1.githubusercontent.com
185.199.110.133 avatars2.githubusercontent.com
185.199.110.133 avatars3.githubusercontent.com
185.199.110.133 avatars4.githubusercontent.com
185.199.110.133 avatars5.githubusercontent.com
185.199.110.133 avatars6.githubusercontent.com
185.199.110.133 avatars7.githubusercontent.com
185.199.110.133 avatars8.githubusercontent.com