(In 2017, teacher Han Ligang published the supporting PPT of "Innovative Course on Computer Network Principles". In the period, there are teacher Han Ligang QQ number 458717185 and WeChat account hanligangdongqing. If you have problems in learning computer network principles, you need the software and documents required for the course, you can connect to teacher Han Ligang and ask for it.
Chapter 7 Network Layer Protocol.pptx)