[ Mini simulated networks ]
https://github.com/mininet/mininet/wiki/Documentation

[ TCP IP guide ]
http://tcpipguide.com/free/t_toc.htm

[ TCP/IP explained ]
http://www.objc.io/issue-10/ip-tcp-http.html

[ Visualization of DNS Query and Response ]
http://m-mizutani.github.io/blog/2014/02/10/dnsviz-en/