This chapter is concerned with the management and maintenance of internetworks. Management should be tackled as a proactive task and should form an integral part of your design strategy. Maintenance is all too often a reactive task, dealing with unforeseen problems and diagnosing network failures. Network management becomes a key concern as networks grow in both size and complexity. As the number of devices, services, users, and sites begins to multiply, so do the network manager's activities and responsibilities. In a large commercial internetwork, it may be critical to identify problems and resolve them in a matter of minutes. You need to identify and resolve problems before they become serious enough to jeopardize the business. Remote devices may need to be monitored, closed down, and restarted. Faults must be clearly reported, understood, and acted upon. Inefficiency, overloading, and degraded performance should be diagnosed and resolved proactively. To achieve all this, management centers and managed devices must be capable of communicating with one another. These functions are commonly referred to as a Management Information Services (MIS). If the network is designed properly from the ground up, the MIS should be used as a proactive tool to monitor the network and work out where performance can be improved and cost savings made. Value-added services (such as advanced network monitoring and modeling tools) can be built into this basic structure. In a badly designed network you will spend the majority of your time fire fighting.

Perhaps the two classic vendor architectures are...