Linux ubuntu16

open the terminal, input the command:

　　sudo -i gedit /etc/hosts file

click enter key, then input your password, click enter key, the hosts file will be open, now you can edit it.

Windows (win7/win8)

　　C:\Windows\System32\driver\etc\hosts

open the hosts, now you can edit it.

在Linux/Windows系统上编辑/etc/hosts文件