Transcript Business Data Communications and Networking

Topic 11:
Network Management
References:
FD – Chapter 12
WS – Chapter 19
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New challenges in Network
Management
The Shift to LANs and the Web
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Technical compatibility of technologies and protocols
The cultural differences in personalities and management
styles of network managers.
Integrating LANs, WANs, and the Web
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Both LAN/Web and WAN managers recognize that they no
longer have the power they once had.
Integrating Voice and Data Communications
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Issues in Network
Management
Configuration Management
Performance Management
Fault Management
End-user management
Cost Management
Security Management
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Configuration Management
Configuring the Network and Client
Computers
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Adding and deleting user accounts.
updating the software on the client
computers
Documenting the Configuration
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includes information about network hardware,
network software, user and application profiles,
and network documentation.
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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.
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Performance and Fault
Management
Network Monitoring
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physical network statistics and logical
network information.
Failure Control
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Trouble tickets
Problem tracking
Problem statistics
Problem prioritization
trouble log
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Performance and Fault
Management
Problem resolution
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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.
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End-User Support
Solving whatever problems users
encounter while using the network.
Three types:
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Resolving network problems
Resolving software problems
Training
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Cost Management
Sources of Costs
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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.
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Sources of costs
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NETWORK MANAGEMENT TOOLS
Network Management Software
Network Management Standards
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SNMP (SNMPv2, SNMPv3)
CMIP
RMON and RMON2
Network Management Hardware
Examples of the Network Management Software
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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:
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Device management software
System management software
Application management software
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Network Management Standards
The two most commonly used network
management protocols are:
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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
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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.
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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:
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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:
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analog testing - the analog side of the modem
digital testing - digital communications circuits
protocol testing - procedures, packets and messages.
Testing hardware includes:
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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
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Ethernet (802.3) 10 Mb/100 Mb
Token Ring (802.5)
Serial Line
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*Demonstration
http://www.rad.com/networks/1998/sn
mp/snmp.html
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