(Content introduction: this book is the first of the designated textbooks for intermediate training and certification of "national network management technology level examination" (NMSE) (network management certification). It introduces all the professional practical skills that must be mastered in the network management of large and medium-sized enterprises. The book has 12 chapters and is divided into three parts: advanced Windows domain management and application (mainly including the layout equipment of domain controllers in multi domain environment, the layout equipment of DNS servers in multi domain and multi DNS server environment, the layout equipment of site imitation and domain trust, and the equipment and management of exchangeserver2003 mail server in multi domain environment) Redhatenterpriselinux5 system management and server equipment (such as RHEL5 system and program devices, RHEL5 system user, file and authority management, rhel5dns, DHCP and Samba server deepening equipment, etc.), Cisco switch and router equipment and management (mainly including Cisco switch and router network operating system application, layer 2 / 3 interface, VLAN, STP, VTP, routing, NAT equipment and management, etc.). The contents introduced in this book are introduced in a full, systematic and in-depth manner (not in general terms) with many simulation examples, covering some of the primary contents of the actual operation of network management in large and medium-sized enterprises. This book combines the other two certified textbooks at the same level: the network engineering plan and planning of the gold medal network administrator (intermediate) and the network test manual of the gold medal network administrator (intermediate) together to form a relatively complete common sense system for network management of large and medium-sized enterprises.)