(This book mainly analyzes the typical and common faults in the network, including the fault diagnosis and removal of local area network clients, switches, routers, etc. From a useful point of view, combined with the author's practical experience, gives a brief and highly operable. Solutions can help readers develop excellent problem-solving habits. This book also briefly introduces commonly used detection tools, such as line measuring instruments and network multimeters. This book can not only be used as a guide for network administrators to clear faults, but also a reference book for students of relevant majors, beginners who want to enter the field of network management, and primary network administrators.)