MAC无法 ping 通github 系列主页

检索能够解析github.com的ip

https://tool.chinaz.com/speedworld/github.com
从列表中选总解析时间最快的ip地址：

复制ip地址作为github.com路由转发表

sudo vim /etc/hosts

##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
##
127.0.0.1       localhost
255.255.255.255 broadcasthost
::1             localhost
20.200.245.247 github.com

输入:q!保存后退出编辑器；

刷新DNS，键入以下命令

dscacheutil -flushcache