Intranet System Management

Question 1

Motivations for Network Management

Answer 1

Computer networks become mission-critical
-Down time in IT systems cause problems for industry
-Organisational asset

Question 2

Goals for Network Management

Answer 2

Need responsive network management
-Help desk
-Network support technicians
-Network Systems Management
-Monitors the network
-Providing the ability to diagnose and control the network

Question 3

Network Systems Management

Answer 3

• Runs on a simple workstation (PC)
• Monitors the network
• Displays the current situation/status
• Identifies “trigger points”
• Notifies Problems as they arise
• Identifies causes
• Supports remote diagnostics
• Intelligent network management
• Self Healing Networks

Question 4

TCP/IP Network Management

Answer 4

Network management involves three distinct needs
- Protocol to write/read critical network management data
- E.G. Event reports
- Database of specific parameters
- e.g. queue-length, throughput etc
- A computer independent definition of the parameters

Question 5

TCP/IP Network Management met by

Answer 5

SNMP: Simple Network Management Protocols
-Read/write protocol between managers and network devices

MIB: Management Information Bases
-The databases of network management information

SMI: Structure of Management Information
-Computer independent notation to describe the data items

Question 6

Simple Network Management Protocol (SNMP)

Answer 6

The manger needs to be able to monitor and control the agent devices

To be able to:
- Read the value of the individual parameters (SNMP Get)
- Read sequences of table entries (SNMP Get_Next)
- Write into parameter values (SNMP Set)
- Receive unsolicited event reports (SNMP Trap)

These events and parameters are the MIBs which are documents using SMI notation

Question 7

Remote MONitor (RMON)

Answer 7

SNMP MIBs include Remote Monitor capabilities

RMON implementation
- Independent probe devices(software) attached to each LAN segment
- Can be integrated into networking devices
-Has a performance impact!

Question 8

RMON

Answer 8

Available in two forms
-RMON 1 monitors OSI layers 1 and 2
-Collision statistics and error statistics
-RMON 2 includes monitoring of higher levels
-Hosts and what application cause the most traffic etc

Can be cost effective, helps control traffic throughput.

Increases the effectiveness of network management personnel and Identifies where the problems are for trouble shooting.

Question 9

Network Management Areas

Answer 9

OSI identifies five areas of network management:
-Configuration
-Fault management
-Performance management
-Accounting management
-Security management

Question 10

Configuration Management

Answer 10

Includes a wide range of issues
-Address and name assignments to network devices
-Hardware/software updates to Switches, routers
-Software license control etc.

Question 11

Configuration Management various parameters

Answer 11

-Configure Switch and routers to filter out certain types of traffic

-Multi protocol routers can be configured to run selected protocols

-Configuration of bit rate, parity etc

Question 12

Fault Management

Answer 12

Fault Management Provides:
-Identification and isolation of faults detected

Tools and Techniques include:
-Bit-Error Rate Test (BERT)
-Time Domain Reflectometer (TDR)
-Optical TDR (OTDR)
-Protocol analyzer (for data links and LANs)
-Used for troubleshooting all protocol layers
-Loopback Tests
-Ping
-Artificial Traffic Generation

Question 13

Fault Isolation – LAN’s

Answer 13

Limiting faults is possible by isolating the fault using switches and router configurations

All traffic across the LAN can be monitored

All exceptional conditions can be detected (collisions, lost tokens, etc)

Devices called LAN analyzers (or LAN protocol analyzers) can be attached to the network
-Selectively record information about packets of interest
-May be set up to filter based on address, protocol, or other fields(s) of interest

Question 14

Network performance management:

Answer 14

Concerned with statistical data
-Round trip delays
-Throughput
May require prioritization of certain traffic
-Including other QoS capabilities
Tuning of performance (eliminating bottlenecks)
-Buffer size adjustments
-Setting timer values
Establishing a baseline
-Adequate minimum system performance required

Question 15

Performance Management cont

Answer 15

Performance management is also concerned with finding bottlenecks
-Wide area links between remote switches and routers
-Access to servers resources e.g. disk storage
-Parts of the network that are nearing overload

Many fault-management tools are useful in performance management

Question 16

Accounting Management

Answer 16

Can be the billing for network usage

Accounting parameters normally include the
-Number of connections made
-Duration of each connection
-Number of e-mail messages sent and received
-Number of packets sent and received
-Systems that are accessed across the network
-Internet usage.

Question 17

Accounting Management cont

Answer 17

-Accounting management may be broadened to include other network attached resources
-Server usage (connect time and disk storage)
-Traffic that needs access to expensive WAN circuits
-Data storage

-Accounting management may also be used to place limits on the use of network resources

-Disc storage space

Question 18

Security Management includes

Answer 18

-Confidentiality
-Integrity
-Authentication
-Access control
-Nonrepudiation

Question 19

Security Management Vulnerabilities

Answer 19

-Wiretaps placed on cables
-Outsiders intercepting Remote login attempts from across the network
-Introduction of a virus

Question 20

Security protection mechanisms include

Answer 20

-Encryption
-Physical protection
-Access-control lists
-Audit data collection