NET311 Computer Network Management Tools, Systems and Engineering

Transcription

1 NET311 Computer Network Management Tools, Systems and Engineering Dr. Mostafa H. Dahshan Department of Computer Engineering College of Computer and Information Sciences King Saud University

2 Acknowledgements Notes are based on slides of: Network Management: Principles and Practice, 2E, Mani Subramanian. 2

3 Basic Network Software Tools Status monitoring tools Traffic monitoring tools Route monitoring tools Basic tools are available as Part of the Operating System Add-on applications 3

4 Status Monitoring Tools Name OS Description ifconfig UNIX/Linux Obtains and configures networking interface parameters and status netsh Windows Displays or modifies the network configuration of a computer ping UNIX/Linux Checks the status of node / host Windows nslookup UNIX/Linux Looks up DNS for name-ip address translation Windows dig UNIX/Linux Queries DNS server host UNIX/Linux Displays information on Internet hosts / domains 4

5 Ifconfig Used to assign/read an address to/of an interface Option -a is to display all interfaces 5

6 Netsh Allows displaying or modify the network configuration in Windows 6

7 Ping Most basic tool for internet management Based on ICMP ECHO_REQUEST message Available on all TCP/IP stacks Useful for measuring connectivity Useful for measuring packet loss Can do auto discovery of TCP/IP equipped stations on single segment 7

8 Ping 8

9 nslookup An interactive program for querying Internet DNS servers Converts a hostname into an IP address and vice versa querying DNS Useful to identify the subnet a host or node belongs to Lists contents of a domain, displaying DNS record Available with UNIX/Linux and Windows 9

10 Dig Used to gather lots of information on hosts from DNS 10

11 Host Displays host names using DNS 11

12 Traffic Monitoring Tools Name OS Description ping UNIX / Windows Used for measuring roundtrip packet loss bing UNIX Measures point-to-point bandwidth of a link tcpdump UNIX Dumps traffic on a network Wireshark Linux / Windows Graphical tool to capture, inspect, and to save Ethernet packets 12

13 bing Used to determine throughput of a link Uses icmp_echo utility Knowing packet size and delay, calculates bandwidth bing L1 and L2 and the difference yields the bandwidth of link L1-L2 Bandwidth of link L1-L2 could be higher than the intermediate links bing L1 L2 13

14 Wireshark 14

15 tcpdump Command: tcpdump Interprets and prints headers for several network protocols Useful for examining and evaluating the traffic Available in UNIX/Linux 15

16 Network Routing Tools Name OS Description netstat UNIX Displays the contents of various network-related data structures arp rarp UNIX, Windows Displays and modifies the Internet-to-Ethernet address translation tables traceroute UNIX Traces route to a destination with routing delays tracert Windows Traces route to a destination with routing delays 16

17 Network Status Show routing table Show TCP connections 17

18 Route Tracing Command: traceroute (UNIX) / tracert (Windows) TIME-EXCEED error report ICMP Also available from uc.msc.unm.edu Traceroute Uses Discovers route taken by packets from source to destination Useful for diagnosing route failures Useful for detecting bottleneck nodes 18

19 Route Tracing 19

20 SNMP Tools SNMP command-line tools Net-SNMP package contains the SNMP command-line tools SNMP MIB Browser with graphical interface SnmpB ManagineEngine MIB Browser ireasoning MIB Browser SolarWinds SNMP MIB Browser 20

21 SNMP Command Tools Command snmptest snmpget snmpgetnext snmpset snmptrap snmpwalk snmpnetstat Description Interactive tool to get values of several managed objects, one at a time Sends the SNMP GET request PDU, returns the SNMP RESPONSE PDU Sends the SNMP GETNEXT request PDU, returns the SNMP RESPONSE PDU Sends the SNMP SET request PDU, returns the SNMP RESPONSE PDU Sends an SNMP notification to a manager Retrieve a subtree of management values using SNMP GETNEXT requests Displays networking status and configuration information from a network entity via SNMP 21

22 NMS Design NMS Functional Requirements NMS Software Components NMS Server Architecture Discovery Module Performance Manager Fault Manager NMS Client Design 22

23 NMS Functional Requirements Scalability Heterogeneity Geographic spread Real-time response Batch processing Diverse users Local and remote management Ease of use Security Data management 23

24 NMS Software Components NMS Server Centralized Distributed Local NMS / EMS Integrated NMS / MoM NMS Client Local / Console Remote Dedicated Browser-based 24

25 NMS Server Architecture Modular architecture Managed object database Configuration Manager / Discovery Module Fault Manager Performance Manager Module Layers Lower (core) layer: Performs business logic Upper layer: Graphical User Interface (GUI User Interface Mgmt Protocols G U I W e b E m a i l S M S... Config. Mgr Discovery Perf. Mgr Data Collector Reports MODB S N M P C O R B A C M I P Proprietary T C P / U D P I P... Fault Mgr To NEs 25

26 Discovery Module Discovers topology of network Auto-discovery Manual configuration Discovery queries for NEs in specified range of IP Found IP NEs are queried for specific details Discovery process is configures with parameters given in the above table Module 26

27 Discovery Parameters Parameter Value Description IP addresses Wait Interval , / secs SNMP version v1 v1, v2c, or v3 A range or list of IP addresses SNMP community public A commonly-used value Waiting time between discovery of successive IPs to minimize load on the network Discover types Router, server, switch Only elements of these types are added to the MODB Ignore types PC, UPS Elements of these types are not added to the MODB Notes Discovery parameters are set in the discovery configuration file Discovery parameters chosen to manage the scope of NEs discovered and the time for discovery run 27

28 Performance Manager Two major functions Data Collection Analysis and report generation Data Collection Offline: Use local data collector and periodic batch transmittal to NMS. Should have NE id, OID, Value and timestamp Online: For real-time performance analysis 28

29 Performance Manager Online data collection issues Overloading of the server Overloading the network Overloading the agent Poll configuration Database schema 29

30 Fault Manager Event generation: Notification or trap indicator of fault Multiple consecutive status polls fail to receive response Threshold crossing, e.g. performance limit Internal escalation of fault resolution Event filtering of unwanted events Event correlation of repeated receipt of same fault event Conversion of event to alarm by alarm register Root cause analysis of multiple alarms done alarm correlator Alarm indications: Visual, audio, SMS / phone call, , log 30

31 Fault Manager NE Traps Polls Event Detectors Event Event Event Event Event Event Filter Correlator Alarm Register Alarm E Alarm Correlator Timeouts Recent Events Current Alarms Figure 9.31 Path of an Event through the Fault Manager 31

32 NMS Client Design Design approaches Terminal client Graphical (GUI) client Browser or Web client 32

33 Terminal Client dumb character-oriented terminal Terminal emulation software (xterm, Putty) on PC Connection to NMS via telnet or ssh over TCP/IP No GUI 33

34 Graphical Client PC runs special client application that works with server Advantages Graphical interface Runs NMS functionalities Problems Lack of portability Requires update with NMS server update High degree of incompatibility with multiple servers 34

35 Browser or Web Client de-facto standard now Advantages GUI capability Minimal NMS-dependent software in the client Problems Portability between different browsers still a problem, but minimized 35

36 NMS Solutions Commercial HP Network Node Manager NNMi (formerly OpenView) SolarWinds Free OpenNMS Nagios 36

37 References Using Netsh Using PowerShell to Find Connected Network Adapters Net-SNMP Documentation