Network Management Functions - Fault. Network Management

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Penelope Greer
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1 Network Management Functions - Fault Network Management 1

2 Lectures Schedule Week Week 1 Topic Computer Networks - Network Management Architectures & Applications Week 2 Network Management Standards Architectures & Applications Week 3 Simple Network Management Protocol - SNMP v1, ASN, MIB, BER Week 4 Network Management Functions - Fault Week 5 Simple Network Management Protocol - SNMP v2 - Configuration Week 6 Network Management Functions - Accounting Week 7 Simple Network Management Protocol - SNMP v3 - Performance Week 8 Network Management Functions - Security Week 9 Midterm Week 10 Remote Network Monitoring RMON 1, SLA Week 11 Remote Network Monitoring RMON 2 Week 12 Management Tools, Systems and Applications Week 13 NM Project Presentations Week 14 NM Project Presentations Week 15 NM Project Presentations 2

3 Network Management OSI NM Architecture and Model Manager Organization Model Agent Object Information Model Communication Model Structure of Management Information (SMI) Management Information Base (MIB) Protocol Data Unit (PDU) Configuration Management (CM) Fault Management (FM) Functional Model Performance Management (PM) Security Management (SM) Accounting Management (AM) 3

4 Why do we need fault management? To monitor the network and know what s going on? To identify the root cause of network faults? To measure downtime (uptime)? To meet SLA s? Because everybody else does it? Because I ve been told it s important?

5 Fault Management [ISO Definition] Handling errors, faults and alarms in a timely and controlled manner. Error: Deviation of system from normal operations Fault: Physical or algorithmic cause of a malfunction Alarm: Notification of a specific event, may or may not represent an error A fault is an unplanned failure of software, hardware Not every outage is due to a fault Not every fault results in an outage

6 Network Management Functions Corporate Network Management Administration Mgmt Capacity Mgmt Provisioning Mgmt Accounting Mgmt Performance Mgmt Configuration Mgmt Fault Mgmt Security Mgmt Testing Trouble Detection Trouble Analysis Trouble Resolution Trouble Logging

7 Fault Management Fault management - preventing, detecting and correcting any faults in the network circuits, hardware, and software

8 Fault Management Fault Management Detection of a problem, fault isolation and correction to normal operation A goal is to use trend analysis to predict faults and change network conditions so that the network is always available to users FM involves the following steps Discover the problem Isolate the problem Fix the problem (if possible)

9 Fault Management Sub-Categories and Related Activities Prioritization Prioritize faults in the order in which they should be addressed Use in-band management packets to learn about important faults Identify which fault events should cause messages to be sent to the manager Identify which devices should be polled and at what intervals Identify which device parameter values should be collected and how often Prioritize which messages should be stored in the manager s database Timeliness Required Management Station is passive and only receives event notifications Management Station is active and polls for device variable values at required intervals Application periodically requests a service from a service provider Physical Connectivity Testing Using a cable tester to check that links are not broken

10 Fault Management Sub-Categories and Related Activities (cont.) Software Connectivity Using an application that makes a request of another device that Testing requires a response. q The most often application for this is Ping.Exe. It calls the Internet Control Message Protocol ( ICMP) which sends periodic Echo Request messages to a selected device on a TCP/IP network q Application on one device makes a request of an application on another device Device Configuration Devices are configured conservatively to minimize chances of dropped packets. SNMP Polls Devices are periodically polled to collect network statistics Fault Reports Generated Thresholds configured and alarms generated Text media used for report Audio media used for report A color graphical display used to show down devices Human manager is notified by pager Traffic Monitored Remote Monitors used Protocol analyzers used Traps sent to Network Management Station Device statistics monitored Trends Graphical trends generated to identify potential faults

11 Example of Fault Management User DNS PC UNIX FDDI RMON Device Firewall UNIX / Router Internet Mail Server WWW Server UNIX... PC PC

12 Failure Control Help desk function human intervention problem reporting authority to call other support or vendors as necessary problem tracking problem statistics troubleshooting chronic device failures

13 Testing and Problem Fix Establish test and validity criteria Coordinate and administer the various tests Quick diagnoses Maintain a variety of testing equipment Document fix procedure Report on problem resolution time Record down time and network availability statistics

14 Fault Management A fault is defined as the cause of one or more observed error, or abnormal, events. Fault Management or Safety management concerns maintaining core ICT service operations. Fault management overlaps with security management How? 14

15 Fault Management Detect the fault type of events that lead to system failure. Organise and manage fault cascades in which a root fault leads to numerous child faults, generally the child faults should be suppressed. Report faults to an appropriate authority or manager. Automatic correction and handling of some faults. 15

16 Fault Management Fault management is crucial for maintaining the operation of critical infrastructures through monitoring, detecting, preventing and anticipating anomaly events E.g., utility distribution, telecomms, transport, logistics, intelligent HVAC, banking, medicine etc. Fault or safety management involves: fault prevention, fault prediction, fault event monitoring, fault detection, fault diagnosis, fault handling fault-tolerance. 16

17 What tools do I need if I get 30 traps per sec sustained on my network? A pen to write my resignation. 17

18 Sources Routers, switches, wires, fiber, PDUs, DNS servers, power companies, squirrels, flooding, soft drinks, clumsy people, nuclear accelerators, bulldozers, users, network managers,

19 Device Fault Management IP fabric

20 Device Fault Manager Device Analysis device level faults Identifies POSSIBLE problems Forwards intelligent traps to enterprise fault systems

21 Monitoring Console Inventory Browser Instance Properties Alarm Log

22 Network Connectivity Monitor

23 What the user will see with NCM Single Problem

NCM Internal Architecture Overview Topology NCM Analysis Server

The Topology is built and updated automatically when discovered

Behavior Models Signatures and impacts are automatically

24 NCM Internal Architecture Overview Topology NCM Analysis Server Object Behavior Models describe problems/symptoms/propagation The Topology is built and updated automatically when discovered Objects are instantiated to entities defined in the Object Behavior Models Signatures and impacts are automatically computed and updated based on the Object Behavior Models and the Topology

25 Authentic Problem Signatures Problems s0 s1 s2 s3 s0 c0 s0 c1 s1 c0 s1 c1 s2 c0 s2 c1 s3 c0 s3 c1 s0 c0 p0 s0c0p0l s0c0p0l s0c0p1l s0c0p1l s0c1p0l s0c1p0l s0c1p1l s0c1p1l s1c0p0l s1c0p0l s1c0p1l s1c0p1l s1c1p0l s1c1p0l s1c1p1l s1c1p1l s2c0p0l s2c0p0l s2c0p1l s2c0p1l s2c1p0l s2c1p0l s2c1p1l s2c1p1l s3c0p0l s3c0p0l s3c0p1l s3c0p1l s3c1p0l s3c1p0l s3c1p1l s3c1p1l s0 c0 p1 s0 c1 p0 s0 c1 p1 s1 c0 p0 s1 c0 p1 s1 c1 p0 s1 c1 p1 s2 c0 p0 s2 c0 p1 s2 c1 p0 s2 c1 p1 s3 c0 p0 s3 c0 p1 s3 c1 p0 s3 c1 p

26 Many Symptoms One Problem 8 different logical ports are down Single fault Switch 1 Card 0 -- Down Switch 0 C0 P0 P1 L0 L1 L0 L1 L0 L0 L1 L0 L1 L0 P0 P1 P0 Card Down C0 Switch 1 C1 P0 P1 L1 L0 L1 L1 L0 L1 P1 C1 Switch 2 C0 C1 P0 P1 P0 P1 L0 L1 L0 L1 L0 L1 L0 L1 L0 L1 L0 L1 L0 L1 L0 L1 P0 P1 P0 P1 C0 C1 Switch 3

27 Why do we need to integrate? Fault Occurs Detection Nominal Fault Management Process Correlation Correction Diagnosis

28 Typical Tool Architecture NMS Alarm Element Ticketing Event Ticket Workflow Customer Ticket Inventory & Location Customer SLA Billing

29 Fault Management Architecture for mid-tier Enterprise Manager of Managers Notification Trouble Tickets CIC, CA Unicenter, etc. Network Management Layer NMS Framework: HP OpenView, Tivoli NetView, etc Element Management Layer Element Layer Non-Cisco EMS, NMS, Devices

30 Services: IP VPN VoIP MPLS ISDN FR ATM DSL VoDSL Cable LMDS DWDM Dial LAN Many more Service Management Layer Network Management Layer Enterprise Databases Impact Policies Correlation & Enrichment Visionary Locates cause of fault Precision topology correlation Fault Management Architecture Notify Responsible Persons for Service Providers Cisco Info Server Event collection and display Service View Event List Optimized for high insertion and deletion rate Policy Manager Filters UG BG UG VPN Solutions Center CNM View Trouble Tickets Reporter RDBMS Element Management Layer Cisco WAN Mgr Cisco Works 2000 C-NOTE CTM Other Optical Dial Element Mgmt. Framework DSL Wireless Cable GSR Other EMs Internet Service Monitors (20+) HTTP DNS Etc. Non-Cisco EMS, NMS, Devices Element Layer

31 Measures: Faults (1/3) Measure MTBF MTTR Availability (should be 99%) Description Mean Time Between Failures Mean Time to Repair The proportion of time when the system is available for use Availability MTBF MTBF MTTR 31

32 Measures: Faults (2/3) Fault Type 4 20 Fault Type 3 40 Fault Type 2 25 Fault Type Frequency distribution of 100 mixed faults associated with 4 types (Measure of Strengths & Weaknesses of Components) 32

33 Measures: Faults (3/3) Weakness Logical Deficiency Description Lack of resources to performing the operations correctly. e.g. Message Reassembly Space in Virtual Circuit Operations Protocol Un-Robustness Lack of built-in fault-tolerant capability to deal with components failures and stress conditions e.g. Routing Problem : Circulation of Packets. 33

34 Conclusion Keep me out of trouble! Let me know when I m having a problem or about to have a problem Support my growing Cisco network as one system Routed and switched environment IP telephony call managers, phones, etc. Network connectivity analysis Don t make me add more staff Out-of-the-box with no rules to write Support new devices in a timely manner Fit into my present mode of operations (PMO)

Network Management Standards Architectures & Applications. Network Management

Network Management Standards Architectures & Applications Network Management 1 Lectures Schedule Week Week 1 Topic Computer Networks - Network Management Architectures & Applications Week 2 Network Management