Topic 11: Network Management

1
Topic 11 Network Management

• References
• FD Chapter 12
• WS Chapter 19

2
New challenges in Network Management

• The Shift to LANs and the Web
• Technical compatibility of technologies and
  protocols
• The cultural differences in personalities and
  management styles of network managers.
• Integrating LANs, WANs, and the Web
• Both LAN/Web and WAN managers recognize that they
  no longer have the power they once had.
• Integrating Voice and Data Communications

3
Issues in Network Management

• Configuration Management
• Performance Management
• Fault Management
• End-user management
• Cost Management
• Security Management

4
Configuration Management

• Configuring the Network and Client Computers
• Adding and deleting user accounts.
• updating the software on the client computers
• Documenting the Configuration
• includes information about network hardware,
  network software, user and application profiles,
  and network documentation.

5
Performance and Fault Management

• Performance management ensuring the network is
  operating as efficiently as possible.
• Fault management preventing, detecting, and
  correcting faults in the network circuits,
  hardware, and software.

6
Performance and Fault Management

• Network Monitoring
• physical network statistics and logical network
  information.
• Failure Control
• Trouble tickets
• Problem tracking
• Problem statistics
• Problem prioritization
• trouble log

7
Performance and Fault Management

• Problem resolution
• The purpose of testing and problem management is
  to establish test and validity criteria and
  coordinate the various tests.
• The network network operations group use
  automated network management software to gather a
  daily record of the normal operations of the
  network. These data can be used for predicting
  future growth patterns and failures.
• More organizations are beginning to establish
  service load agreements with their common
  carriers and service providers, which specifies
  the type of performance and fault conditions that
  the organization will accept.

8
End-User Support

• Solving whatever problems users encounter while
  using the network.
• Three types
• Resolving network problems
• Resolving software problems
• Training

9
Cost Management

• Sources of Costs
• The total cost of ownership (TCO) is a measure of
  how much it costs per year to keep one computer
  operating. Many studies for TCO indicate it can
  cost up to five time the value of the computer to
  keep it operational.
• Since the largest cost item is personnel time,
  the primary focus of cost management lies in
  designing networks and developing policies to
  reduce personnel time, not reduce hardware costs.

10
Sources of costs
11
NETWORK MANAGEMENT TOOLS

• Network Management Software
• Network Management Standards
• SNMP (SNMPv2, SNMPv3)
• CMIP
• RMON and RMON2
• Network Management Hardware
• Examples of the Network Management Software
• MRTG
• LANWatch32

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Network Management Software

• Network management software is designed to
  provide automated support for some or all of the
  network management functions.
• There are three fundamentally different types of
  network management software
• Device management software
• System management software
• Application management software

13
Network Management Standards

• The two most commonly used network management
  protocols are
• Simple Network Management Protocol (SNMP)
• Common Management Interface Protocol (CMIP)

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Network Management Console
Managed Device with SNMP Agent
Managed Device with SNMP Agent
Switch
Switch
MIB stored on Server
Managed Device with SNMP Agent
Managed Device with SNMP Agent
Switch
Managed Device with SNMP Agent
Router
Switch
Managed Device with SNMP Agent
Switch
To Core Backbone
Figure 12-7 Network Management with SNMP
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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) .
• 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.

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Role of SNMP
Transmission of a message Receipt of a
message Variable bindings
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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.

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SNMPv2

• Released in 1992, revised in 1996
• Addressed functional deficiencies in SNMP
• Accommodates decentralized network management
• Improves efficiency of data transfer

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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

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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.

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Remote Monitoring (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

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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.

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RMON

• The first version of the RMON MIB standard uses
  SNMP, the most popular network management
  protocol, to monitor the basic operations of
  Ethernet and Token Ring.
• The first RMON standard, RFC 1271, defines two
  Ethernet-specific groups and seven other groups
  that apply to both Token Ring and Ethernet.
• The second standard, RFC 1513, defines Token Ring
  extensions to RMON. With these first two
  standards, RMON laid a foundation for future
  extensions to the MIB as new network technologies
  emerged.
• Today, the standard includes 13 defined Ethernet
  and Token Ring MIB groups that contribute to the
  standard's ultimate goal to enable
  vendor-independent monitoring of all LANs,
  provided the monitoring agents are RMON-compliant.

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RMON and RMON2
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Network Management Hardware

• Network management hardware is used for circuit
  testing
• analog testing - the analog side of the modem
• digital testing - digital communications circuits
• protocol testing - procedures, packets and
  messages.
• Testing hardware includes
• Monitors and analyzers
• Analog and Digital test sets
• Patch panels
• Data recorders
• Handheld test sets

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Multi-Router Traffic Grapher (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.
• 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).

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LANWatch32

• Precision Guesswork's LANWatch32 Network Analyzer
  for Windows 95/NT is a software solution
  targeting the complex task of network analysis.
• 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

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Demonstration

• http//www.rad.com/networks/1998/snmp/snmp.html