Chapter 19: Network Management Business Data Communications, 4e

2 Network Management Requirements  Fault Management  Accounting Management  Configuration and Name Management  Performance Management  Security Management

Business Data Communications, 4e3 Fault Management  A fault is an abnormal condition that requires management attention (or action) to repair  Fault is usually indicated by failure to operate correctly or by excessive errors  Users expect quick and reliable resolution

Business Data Communications, 4e4 Accounting Management  Reasons for accounting management: Internal chargebacks on network use User(s) may be abusing access privileges and burdening the network at the expense of other users Users may be making inefficient use of the network The network manager is in a better position to plan for network growth if user activity is known in sufficient detail.

Business Data Communications, 4e5 Configuration Management  Concerned with: initializing a network and grace-fully shutting down part or all of the network maintaining, adding, and updating the relationships among components and the status of components themselves during network operation

Business Data Communications, 4e6 Performance Management  Issues of concern to the network manager include: 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?  Network managers need performance statistics to help them plan, manage, and maintain large networks

Business Data Communications, 4e7 Security Management  Concerned with generating, distributing, and storing encryption keys monitoring and controlling access to networks access to all or part of the network management information collection, storage, and examination of audit records and security logs

Business Data Communications, 4e8 Network Management Systems  Collection of tools for network monitoring and control, integrated in these ways: A single user-friendly operator interface for performing most or all network management tasks A minimal amount of separate equipment  consists of incremental hardware and software additions implemented among existing network components

Business Data Communications, 4e9 Network Management System Architecture

Business Data Communications, 4e10 Components of the NMS  All nodes run the Network Management Entity (NME) software  Network control host or manager runs the Network Management Application (NMA)  Other nodes are considered agents

Business Data Communications, 4e11 Network Monitoring Systems

Business Data Communications, 4e12 Simple Network Management Protocol (SNMP)  Designed in the mid-1980's as an answer to the communication problems between different types of networks.  Consists of a simply composed set of network communication specifications that cover all the basics of network management in a method that poses little stress on an existing network.  Each SNMP device (router, gateway, server) has an agent that collects information about itself and the message it processes, and stores that information in a database called the management information base (MIB).

Business Data Communications, 4e13 Role of SNMP  Transmission of a message  Receipt of a message  Variable bindings

Business Data Communications, 4e14 SNMP  The network management software has access to these MIBs. A network manager can use this software to send control messages to individual devices or groups of devices asking them to report the information stored in their MIB.  Network information is exchanged through the messages called protocol data units (PDU's). The PDU can be looked at as an object that contains variables that have both titles and values.

Business Data Communications, 4e15 SNMP  Five types of PDU's employed to monitor a network: two deal with reading terminal data, two deal with setting terminal data, and one, the trap, is used for monitoring network events such as terminal start-ups or shut-downs.  To see if a terminal is attached to the network, a user uses SNMP to send out a read PDU to that terminal. If the terminal was attached to the network, the user would receive back the PDU, it's value being "yes, the terminal is attached". If the terminal was shut off, the user would receive a packet informing them of the shutdown.

Business Data Communications, 4e16 SNMPv2  Released in 1992, revised in 1996  Addressed functional deficiencies in SNMP  Accommodates decentralized network management  Improves efficiency of data transfer

Business Data Communications, 4e17 SNMPv3  Released in 1998, addressed security deficiencies in SNMP and SNMPv2  Does not provide a complete SNMP capability; defines an overall SNMP architecture and a set of security capabilities for use with SNMPv2  Provides three important services: authentication, privacy, and access control

Business Data Communications, 4e18 Common Management Interface Protocol (CMIP)  CMIP was designed to build on SNMP by making up for SNMP's shortcomings and becoming a bigger, more detailed network manager. Its basic design is similar to SNMP, whereby PDU's are employed as variables to monitor a network. CMIP however contains 11 types of PDU's.  The biggest feature of the CMIP protocol is that its variables not only relay information to and from the terminal (as in SNMP), but they can also be used to perform tasks that would be impossible under SNMP.  Problem: Too wonderful to be implemented.

Business Data Communications, 4e19 Remote Monitoring (RMON)RMON  A standard that provides managers with real-time network and application data for LANs.  The major benefits of RMON: Powerful Monitoring and Analysis Historical Trending of the Local Segment Traditional Protocol Decode Functions Centralized Monitoring of Remote Sites Multi-vendor Interoperability Event Creation on Reaching Predefined Thresholds  RMON is supported by SNMP  Newer version is RMON2

Business Data Communications, 4e20 How RMON Works  Enables MIB information to be stored on the device itself or on distributed RMON probes that store MIB information closer to the devices that generate it.  No transmission from MIB to the central server until requesting the data.  RMON reduces network traffic.

Business Data Communications, 4e21 *RMON and RMON2

Business Data Communications, 4e22 *Multi-Router Traffic Grapher (MRTG)MRTG  MRTG is a tool to monitor the traffic load on network-links.  MRTG generates HTML pages containing GIF images which provide a LIVE visual representation of this traffic.LIVE visual  MRTG is based on Perl and C and works under UNIX and Windows NT.  MRTG is being successfully used on many sites around the net. (MRTG-Site-Map).MRTG-Site-Map

Business Data Communications, 4e23 *LANWatch32  Precision Guesswork's LANWatch32 Network Analyzer for Windows 95/NT is a software solution targeting the complex task of network analysis. Precision Guesswork's  Decodes over 60 network protocols, including: TCP, UDP, IP, IPv6, NFS, NFS (version 3), NetWare, SNA, AppleTalk, VINES, ARP, and NetBIOS.  Media Supported Ethernet (802.3) 10 Mb/100 Mb Token Ring (802.5) Serial Line

Business Data Communications, 4e24 *Demonstration  mp/snmp.html mp/snmp.html