TCP/IP协议

参考资料：

• https://www.liaoxuefeng.com/wiki/1016959663602400/1017787663253120
• https://zhuanlan.zhihu.com/p/363716959
• https://blog.csdn.net/weixin_53186633/article/details/120514627
• https://blog.csdn.net/stone_tmp/article/details/118386484 (得看，整个会员也得看)
• https://www.runoob.com/tcpip/tcpip-tutorial.html