域名相关知识
DNS学习:
https://www.ze3kr.com/2016/12/domain-name-system/
http://blog.csdn.net/yipiankongbai/article/details/25031461
http://blog.csdn.net/yxwmzouzou/article/details/46643609
http://blog.csdn.net/yipiankongbai/article/details/25031461
IP地址学习:
Read the fucking manual and source code