Basic Functions of a Network Management System.

C H A P T E R 6 Chapter Goal Become familiar with the basic functions of a profit perplexity system. entanglement solicitude Basics Introduction This chapter describes functions gross to most interlock- worry architectures and protocols. It also presents the five conceptual field of operationss of counselling as defined by the International Organization for Standardization (ISO). Subsequent chapters in start IX, engagement anxiety, address specific communicate focusing technologies, protocols, and platforms in more(prenominal) detail. What Is electronic electronic electronic web forethought? profit c atomic number 18 means unalike things to different people. In some cases, it involves a solitary meshwork consultant observe vane activity with an outdated protocol analyzer. In some early(a) cases, network management involves a distributed database, autopolling of network devices, and high-end workstation generating real-time graphical views of network topogr aphic anatomy changes and traffic. In general, network management is a service that employs a kind of tools, applications, and devices to assist human network managers in proctoring and maintaining networks. A historical PerspectiveThe primordial 1980s saw tremendous expansion in the argona of network deployment. As companies realized the cost benefits and productivity gains created by network technology, they began to add networks and expand existing networks almost as rapidly as new network technologies and products were introduced. By the mid-1980s, certain companies were experiencing growing pains from deploying some different (and sometimes incompatible) network technologies. The hassles associated with network expansion affect both day-to-day network operation management and strategic network process planning.Each new network technology requires its own establish of experts. In the early 1980s, the staffing requirements alone for managing large, heterogeneous networks c reated a crisis for many organizations. An urgent need arose for automated network management (including what is typically called network capacity planning) integrated crossways diverse environments. Internetworking Technologies Handbook 1-58705-001-3 6-1 Chapter 6 entanglement charge Architecture profits solicitude Basics Network counsel Architecture Most network management architectures use the same basic structure and set of relationships.End stations (managed devices), such as computer systems and other network devices, run software system that enables them to send watchfuls when they recognize problems (for example, when one or more user-determined thresholds are exceeded). Upon receiving these alerts, management entities are programmed to react by executing one, several, or a separate of actions, including operator notification, event put down, system shutdown, and automatic attempts at system repair. Management entities also plunder poll end stations to check the v alue of certain multivariates.Polling finish be automatic or user-initiated, but agents in the managed devices respond to all polls. Agents are software modules that first compile education about the managed devices in which they reside, then store this reading in a management database, and finally provide it (proactively or reactively) to management entities within network management systems (NMSs) via a network management protocol. Well-known network management protocols include the Simple Network Management Protocol (SNMP) and Common Management Information Protocol (CMIP).Management proxies are entities that provide management study on behalf of other entities. visualise 6-1 depicts a typical network management architecture. Figure 6-1 A Typical Network Management Architecture Maintains Many Relationships Network management system (NMS) Management entity Network management protocol Network Agent Agent Agent Proxy Management database Management database Management database M anaged devices ISO Network Management Model The ISO has contributed a great deal to network standardization.Its network management model is the primary means for understanding the major functions of network management systems. This model consists of five conceptual areas, as discussed in the next sections. Internetworking Technologies Handbook 6-2 1-58705-001-3 Chapter 6 Network Management Basics ISO Network Management Model Performance Management The purpose of achievement management is to measure and make available confused aspects of network consummation so that internetwork performance can be kept up(p) at an acceptable level.Examples of performance variables that might be provided include network throughput, user response times, and confines work. Performance management involves three main steps. First, performance data is gathered on variables of interest to network administrators. Second, the data is analyzed to determine general (baseline) levels. Finally, appropria te performance thresholds are determined for each important variable so that exceeding these thresholds indicates a network problem worthy of attention. Management entities continually monitor performance variables.When a performance threshold is exceeded, an alert is generated and sent to the network management system. Each of the steps just describe is part of the process to set up a reactive system. When performance becomes inconceivable because of an exceeded user-defined threshold, the system reacts by sending a message. Performance management also permits proactive methods For example, network simulation can be apply to project how network growth will affect performance metrics. much(prenominal) simulation can alert administrators to impending problems so that counteractive measures can be taken.Configuration Management The goal of configuration management is to monitor network and system configuration information so that the effects on network operation of various versions of hardware and software elements can be bring in and managed. Each network device has a variety of version information associated with it. An engineering workstation, for example, may be configured as follows Operating system, variate 3. 2 Ethernet interface, var. 5. 4 TCP/IP software, Version 2. 0 NetWare software, Version 4. 1 NFS software, Version 5. 1 Serial communications controller, Version 1. X. 25 software, Version 1. 0 SNMP software, Version 3. 1 Configuration management subsystems store this information in a database for easy doorway. When a problem occurs, this database can be searched for clues that may help solve the problem. Accounting Management The goal of account management is to measure network utilization parameters so that individual or group uses on the network can be regulated appropriately. Such regulation minimizes network problems (because network resources can be apportioned based on resource capacities) and maximizes the fairness of network nark across all users.Internetworking Technologies Handbook 1-58705-001-3 6-3 Chapter 6 Review Questions Network Management Basics As with performance management, the first step toward appropriate accounting management is to measure utilization of all important network resources. epitome of the results provides insight into current usage patterns, and usage quotas can be set at this point. Some correction, of course, will be required to reach optimal access practices. From this point, ongoing measurement of resource use can hand over billing information as well as information utilise to assess continued fair and optimal resource utilization.Fault Management The goal of fault management is to detect, log, appreciate users of, and (to the extent possible) automatically fix network problems to keep the network running effectively. Because faults can cause downtime or unacceptable network degradation, fault management is perhaps the most widely use of the ISO network management el ements. Fault management involves first determining symptoms and single out the problem. Then the problem is fixed and the solution is tested on essential subsystems.Finally, the detection and resolution of the problem is recorded. protective covering Management The goal of auspices management is to control access to network resources jibe to local guidelines so that the network cannot be sabotaged (intentionally or unintentionally) and thin information cannot be accessed by those without appropriate authorization. A security management subsystem, for example, can monitor users logging on to a network resource and can refuse access to those who enter inappropriate access codes.Security management subsystems work by dislocation network resources into authorized and unauthorized areas. For some users, access to any network resource is inappropriate, mostly because such users are usually company outsiders. For other (internal) network users, access to information originating fro m a particular department is inappropriate. entrance money to Human Resource files, for example, is inappropriate for most users outside the Human Resources department. Security management subsystems perform several functions.They identify sensitive network resources (including systems, files, and other entities) and determine mappings between sensitive network resources and user sets. They also monitor access points to sensitive network resources and log inappropriate access to sensitive network resources. Review Questions QName the different areas of network management. AConfiguration, accounting, fault, security, and performance. QWhat are the goals of performance management? AMeasure and make available various aspects of network performance so that internetwork performance can be maintained at an acceptable level.QWhat are the goals of configuration management? A monitor lizard network and system configuration information so that the effects on network operation of various vers ions of hardware and software elements can be tracked and managed. QWhat are the goals of accounting management? Internetworking Technologies Handbook 6-4 1-58705-001-3 Chapter 6 Network Management Basics Review Questions AMeasure network utilization parameters so that individual or group uses on the network can be regulated appropriately. QWhat are the goals of fault management?ADetect, log, notify users of, and automatically fix network problems to keep the network running effectively. QWhat are the goals of security management? AControl access to network resources according to local guidelines so that the network cannot be sabotaged and so that sensitive information cannot be accessed by those without appropriate authorization. Internetworking Technologies Handbook 1-58705-001-3 6-5 Chapter 6 Review Questions Network Management Basics Internetworking Technologies Handbook 6-6 1-58705-001-3