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Network Management Basics • Network management requirements • OSI Management Functional Areas – Network monitoring: performance, fault, accounting – Network control: configuration, security • Standardization in network management • Practical issue: introduction to SNMP WWW.BZUPAGES.COM Network Management Requirements Example of approach • Controlling strategic assets • Controlling complexity • Improving service • Balancing various needs: performance, availability, security, cost • Reducing downtime • Controlling costs WWW.BZUPAGES.COM Network Management OSI functional areas • Fault management – Detect the fault – Determine exactly where the fault is – Isolate the rest of the network from the failure so that it can continue to function – Reconfigure or modify the network in such a way as to minimize the impact – Repair or replace the failed components – Tests: connectivity, data integrity, response-time, …. WWW.BZUPAGES.COM Network Management OSI functional areas • Fault management • • • • • • • • Monitoring network and system state. Responding and reacting to alarms. Diagnosing fault causes (i.e., fault isolation and root-cause analysis). Establishing error propagation. Introducing and checking error recovery measures (i.e., testing and verification). Operating trouble ticket systems. Providing assistance to users (user help desk). WWW.BZUPAGES.COM Network Management OSI functional areas • Fault management • • • • • • • • The following technical capabilities and important aids for fault management can assist in fault analysis: Self-identification of system components. Separate testability of components. Trace facility (i.e., keeping records of switched message traffic or labeling messages for the purpose of traceability or special compatibility reports). Error logs. Message echoes at all protocol layers (i.e., at transmission links and on an endtoend basis), such as “heartbeat” or “keep alive” messages that detect failure. Retrieval possibilities for memory dumps. Start possibilities (which can also be initiated and monitored centrally) for selftest. WWW.BZUPAGES.COM Network Management OSI functional areas • Fault management • • • • ping and trace route analysis of network reachability. Triggering of planned resets and restarts (directed to specific ports, port groups,and components). Availability of special test systems (e.g. interface checkers, protocol analyzers, hardware monitors for line supervision). Support of filter mechanisms for fault messages or alarms and event WWW.BZUPAGES.COM Network Management OSI functional classification • Performance management: – – – – – What is the level of capacity utilization? Is there excessive traffic? Has throughput been reduced to unacceptable levels? Are there bottlenecks? Is response time increasing? – Indicators: availability, response time, accuracy throughput, utilization WWW.BZUPAGES.COM service efficiency Network Management OSI functional classification • Performance management: • • • • • • • • • Vertical QOS mapping (e.g. speech quality) Horizontal QOS mapping (e.g. protocols) Establishing QoS parameters and metrics. Monitoring all resources for performance bottlenecks and threshold crossings. Carrying out measurements and trend analysis to predict failure before it occurs. Evaluating history logs (i.e., records on system activity, error files). Processing measurement data and compiling performance reports. Carrying out performance and capacity planning. Description of reactions to changes of the QoS parameters mentioned earlier. WWW.BZUPAGES.COM Network Management OSI functional classification • Configuration and Name Management: – – – – – – – – – – A description of a distributed system The process of configuration Installation of new hardware/software Tracking changes in control configuration Who, what and why? - network topology User interface of the configurator Location of configuration Storage of configuration Validity of configuration The result of a configuration process WWW.BZUPAGES.COM Network Management OSI functional classification • Configuration and Name Management: – – – – – Revert/undo changes Change management Configuration audit Does it do what was intended Tools for Configuration Management WWW.BZUPAGES.COM Network Management OSI functional classification • Security management • Passive attacks: theft of information (passwords, etc.). • Active attacks: masquerades (i.e., users pretending to be someone else, or • repeating, giving priority to or delaying message; (unauthorized access, viruses, Trojan horses, denial-of-service attacks). • Malfunctioning of resources. • Faulty or inappropriate behavior and incorrect response operation. • Security services: generating, distributing, storing of encryption keys for services • Exception alarm generation, detection of problems • Backups, data security • Security logging WWW.BZUPAGES.COM Network Management OSI functional classification • Break down of security management tasks • Conducting threat analyses. • Defining and enforcing security policies. • Checking identity (authentication based on signatures, certificates). • Carrying out and enforcing access controls. • Guaranteeing confidentiality (encryption). • Ensuring data integrity (message authentication). • Monitoring systems to prevent threats to security. • Reporting on security status and violations or attempted violations. WWW.BZUPAGES.COM Network Management OSI functional classification • Accounting management – Identifying consumers and suppliers of network resources - users and groups – Mapping network resources consumption to customer identity – Billing WWW.BZUPAGES.COM Organizational Aspects of Management • Specifying interfaces between domains to enable the exchange of management • information and the invocation of management actions. • Planning and establishing a management infrastructure. • defining procedures for implementing the management processes • the tool functionality required. • Establishing an operational and organizational structure for carrying out management. WWW.BZUPAGES.COM Organizational Aspects of Management • • • • • • Organizational structure of a particular company (teams, groups, departments, operating areas). Geographical conditions (country, location, campus, building). Business areas. Data processing–related aspects (e.g., LAN/WAN, central/distributed DP) Types of resources (hardware, system software, applications software, data, operating materials, premises, technical infrastructure). WWW.BZUPAGES.COM Network Management Scenario WWW.BZUPAGES.COM Management Information • • • • Manager Agent Management Agent Establishing a Common Terminology Between Manager and Agent – Same meaning of objects and term WWW.BZUPAGES.COM Management Information • Management information base – – – – – – – – – The Managed Device as a Conceptual Data Store The MIB is not the same as a database One kind of information One aspect Physical aspect Logical aspect Manager can manipulate the information in MIB Managed object (MO) Real resource WWW.BZUPAGES.COM Management Information WWW.BZUPAGES.COM Management Information • Categories of Management Information • State information – current state of physical and logical resources – current alarm conditions – Current CPU load, and utilization of bandwidth and memory. • Physical configuration information – device type – physical configuration in terms of cards and available ports – MAC addresses – configuration information changes only rarely – Stored WWW.BZUPAGES.COM Management Information • Categories of Management Information • Logical configuration information – IP addresses – telephone numbers – logical interfaces – can be changed by management applications and administrators – startup configuration information – transient configuration information WWW.BZUPAGES.COM Management Information • Categories of Management Information • Historical information – This includes historical snapshots of performance-related state – It is not the part of MIB – It is simply “data” that is stored at the device The Difference Between a MIB and a Database • Footprint • general-purpose processing capabilities. • Specific management requirements • Real effects • Real world resource • Characteristics of the contained data WWW.BZUPAGES.COM Management Information • Categories of Management Information • The Relationship Between MIBs and Management Protocols – SNMP – Structure of Management Information (SMI) – MIB does not depend on any particular management protocol – HTML – Protocol is depended on MIB WWW.BZUPAGES.COM Management Information WWW.BZUPAGES.COM Network Management Some ideas • Managed objects: functions provided by the network • Element Management Systems (EMS): managing a specific portion of the network (may manage async lines, multiplexers, routers) • Managers of Manager Systems (MoM): integrate together information from several EMS WWW.BZUPAGES.COM Network Management Standards • Internet approach: Simple Network Management Protocol (SNMP, secure SNMP, SNMP v2) • OSI approach: CMIP - common management information protocol, CMIS - common management information service (user interface) We concentrate on SNMP WWW.BZUPAGES.COM Network Management Proprietary solutions • The world of Microsoft PC software: Windows NT + several (or hundreds) of PCs with Windows 95 (98??) • Solution: Microsoft SMS software: full control over workstations (Windows95) from central NT server software configuration, updates, full inventory • NT world - incorporates SNMP mechanisms WWW.BZUPAGES.COM