From Chapter 20 of UNIX Systems Administration Handbook, Third Edition Because networks increase the number of interdependencies among machines, they tend to magnify problems.
Network management is the art and science of keeping a network healthy.
Just test the network thoroughly after installation, and check it occasionally to be sure that its load is not excessive. When it breaks, fix it. As your network grows, management procedures should become more automated. On a network consisting of several different subnets joined with switches or routers, you may want to start automating management tasks with shell scripts and simple programs. If you have a WAN or a complex local network, you should consider in-stalling a dedicated network management station with special software.