Network Management
• Management Tools
– Desirable features
• Management Architectures
• Simple Network Management Protocol
Think your PC is expensive?
• Typical PC cost: $1,500
• Typical cost to manage that PC: $7,700*
• Total: $9,200
84 % of costs
stem from
management
* http://www.3com.com/news/releases/pr00/sep1800a.html
Team-work
• Brainstorm: What are the
major problems for
Network Managers?
• Teams: Find solutions!
Key Network Management Functions
• Configuration management
• Performance management
• System tuning and capacity planning
• Fault management
• Security
• Accounting management
Tasks for Network Managers
• Plan, organize, direct, control, staff the voice/data
network operation
• Manage operations and provide support
• Ensure reliability
• Manage LANs and connections to backbone
• Keep abreast of technological developments
• Manage the communications budget
• Evaluate and acquire communications hardware,
software, and services
Hardware Tools for network management
• Cable testers
• Error rate testers
• Protocol analyzers
• Response time monitors
• Self-testing devices.
Software Tools for network management
• Inventory tracking
– Numara Track-it
• License metering
• Software distribution
• Trouble ticketing
• Simulation modeling
• Workload generators
• Network utilization
overviews
Network Management Standards
• OSI Model /CMIP
• International standard (ISO/OSI)
• Management of data communications networks – LAN and WAN
• Deals with all seven layers
• Most complete model
• Object-oriented
• Well structured and layers
• Consumes large resource in implementation
• Internet Model/SNMP
• TMN
• International standard (ITU-T)
• Management of telecommunications network
• Based on OSI network management framework
• Addresses both network and administrative aspects of management
• IEEE LAN/WAN
• IEEE standards adopted internationally
• Addresses management of LANs and MANs
• Adopts OSI standards significantly
• Deals with first two layers of the OSI Reference Model
• Web-based Management
• Uses Web server/Web browser architecture
• Java Management Extensions (JMX)
Simple Network Management
Protocol (SNMP)
What is it?
A Protocol that Facilitates the exchange of management information
between network devices.
Why was it developed?
To control and monitor status of network devices
How is it beneficial?
Enables network administrators to:
Manage network performance
Find and solve network problems
Plan for network growth
SNMP Basic Components
• Network Management station
– Collects and stores management information, and makes this information
available to NMS using SNMP
– Could be a work station or PC
• Network Management System (NMS)
– Executes applications that monitor and control managed devices
• Agent
– A network-management software module that resides in a managed device
• Management Information Base (MIB)
– Used by both the manager and the agent to store and exchange
management information
NMS
User Interface
Network
Management Station
Network
Management
Management Architecture
Application
SNMP
AGENT AGENT AGENT
MIB MIB MIB
Managed
Devices
Router
Host Printer
How SNMP Works
Set-request
Get-request
Get-next-request
traps
Get-response
Network Management MIB
Station SNMP Agent
Get-request: Request value of variable.
Get-next-request: Request the value of next variable (like a table).
Set-request: update one or more variables (for reconfiguration).
Get-response: agents sends a reply to manager.
Traps: agent notifies manager about an abnormal situation.
With a Network Management System, you can monitor a large network from a
central console.
Remote Monitor (RMON)
• A tool to analyzes performance, and monitor information that is gathered
and locally analyzed that can then be transmitted to remote network
segment(s).
• Works on a standalone and distributed agent modes.
• Gathers and feeds information to a network management system. RMON
Client
Ethernet LAN
Segment
Router
Network Management Workstation
Station
WAN
Ethernet LAN
Segment
RMON RMON
Workstation Router
Architecture Client
RMON features
• Monitor station frame counts, byte counts and percentage of traffic
generated
• Assign user names to network addresses
• Show network utilization (GUI interface)
• Identify stations with errors
• Set network alarms, station alarms
• Log network alarm activity to file or printer
• Comprehensive traffic statistics screen
• Test the attached cable
• Generate various hardcopy reports.
Summary
• Network management is becoming increasingly important with
the advent of larger networks
• Network management costs are high
• Automated tools can lower management cost.
• Vendors finally paying belated attention to it.
• Standards such as SNMP and SNMPv2 are now emerging and
are being adopted widely.
A dose of reality
“Raise your hand if you believe that
management standards are going to help you
manage your network. Anyone? That's what we
thought”
“If airline seating operated the way most
networks do, those passengers first in line would
sit in first class“
Source: http://www.networkcomputing.com/1117/1117f3.html?ls=NCJS_1117rt