Introduction to Network Management

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Introduction to Network Management
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Objective of this chapter

• Introduction to Network Management
• Presents a brief overview of network management.
• Network Management Architectures
• Provides a brief overview of the common
  components of network management architectures.
• components of network management system (NMS)
• Open System Interconnection (OSI) Network
  Management Model
• Introduces the ISO OSI network management model.

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Function of Network Management

• Designed to simplify the operation of large
  internetworks. This includes
• control corporate strategic assets from a central
  position
• aids in strategically planning for network
  growth.
• provide remote system management
• operate independently of the system it monitors
• support multiple protocols
• operate as transparently as possible
• improve services - maintaining network stability,
  tuning network performance,
• balance various needs, including applications,
  systems and technologies
• troubleshooting problems that might arise.
• reduce downtime with fast response time
• control costs

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Challenges

• Automated processes
• Repetitive tasks can be performed reliably and
  predictably by automated processes.
• Integration across diverse network environments
  (heterogeneous networks)
• Management capabilities can be made available in
  geographically dispersed environments or in
  networks using multiple protocols or platforms.

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Challenges (2)

• Network monitoring
• Constant monitoring alerts network administrators
  to problems quickly.
• Tracking functions
• Tracking past problems makes finding solutions
  easier, while recording values for performance,
  availability, and other areas can uncover trends
  that might affect future growth.

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Network Management System (NMS)

• A typical model of network management systems
  consists of
• a network management station -- the central
  controller
• the managed device -- network devices like
  routers and gateways which interconnect
  sub-networks
• a protocol for communications, such as SNMP,
  between network devices and the controller, and
• a set of parameters to be monitored and controlled

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Components of NMS

• Network management station
• Managed Device
• agent
• management database
• Network management protocol

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Network Management Station

• The NM station is a computer system that contains
  software processes known as management entities.
• a powerful PC or workstation, normally dedicated
  for continuous use of network management
• should be installed with a network management
  platform (protocol) such as HP OpenView, SUN
  SuNet Manager, IBM NetView.
• normally, network management application tools
  are also required, such as CiscoWorks

Network Management Platform and Applications
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Network Management Station (2)

• Management entities poll agents in managed
  devices (automatically or by user request) to
  check the values of certain variables.
• Management entities also react to alerts from
  managed devices by executing one or more actions,
  such as notifying the network administrator,
  performing event logging, shutting down a system,
  or attempting system repairs.

Network Management Protocols
Management Station
Network Devices
request
write
MIB
replies, trap
read
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Network Management Interactions

• Polling
• network management station NMS queries each
  network devices ND periodically, so, consumes
  more bandwidth.
• NMS sends request message to NDs to get status
  information or set operation parameters (MIB
  variables)
• network devices return reply message carrying
  status information (MIB variables)
• Logging
• Traps -- network devices generate warning
  messages when a critical threshold is reached
• NMS log/record alarm messages and alert the
  network engineers
• event-triggered, so, consumes little bandwidth

request
replies
trap
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Managed Devices

• Managed devices
• Managed devices are systems that fall under the
  control of an NMS.
• Managed devices contain software modules called
  agents.
• Agents compile and store information about the
  managed device in a management database and
  provide this information (proactively or
  reactively) to the NMS.
• Agents define the parameters that an NMS can
  monitor or configure

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Common NM Protocols

• Simple Network Management Protocol (SNMP)
• SNMP is a protocol that facilitates exchange of
  management information between network devices,
  primarily in TCP/IP environments.
• In 1988, the Internet Activities Board IAB
  committee proposed the SNMP as the short-term
  solution for network management.
• Since then, the simple structure and good
  performance of SNMP has make it popular around
  the world. It is likely that SNMP will be a
  long-term solution.
• Remote Monitor (RMON)
• RMON is a standard monitoring specification for
  exchanging network monitoring data.
• Common Management Information Protocol (CMIP)
• An OSI network management protocol created and
  standardized by ISO for the monitoring and
  control of heterogeneous network.

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Network Management Architecture
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NM Architectures model

• Most network management architectures are
  implemented using similar structures and sets of
  relationships.
• Three network management architecture
• Centralized
• Distributed
• Hierarchical
• Regardless the NM architecture, there are two
  basic components in a typical network management
  environment
• Managed devices
• a network host with an agent
• Network Management System (NMS)
• for example HP OpenView

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Centralized Architecture

• all queries are sent to a single management
  system
• applications are installed on the central NMS
• responds to trap messages sent from managed nodes
• strength
• easy to manage
• ideal for small to medium-size networks
• weakness
• NMS can easily be overburdened
• NMS may be bombarded by numerous traps send from
  managed nodes

NMS
Agent
Agent
Agent
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Distributed Architecture

• at least two peer NMS
• distributed architecture is usually for networks
  in different places (geographically)
• strength
• not be overburnded
• suitable for medium to large-sized networks
• load balanced
• provide fault-tolerant
• NMS can poll managed nodes on other areas

NMS
NMS
Agent
Agent
Agent
Agent
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Hierarchical Architecture

• combine a centralized system with a distributed
  system
• most complex architecture
• suitable for large and complex network
  configuration
• Strength
• delegate various tasks and responsibilities to
  sub-systems on the network

Centralized NMS
NMS
NMS
Agent
Agent
Agent
Agent
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ISO-OSI Network Management Model

• also known as FCAPS model

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Open System Interconnection (OSI) NM Model

• The Open System Interconnection (OSI) network
  management model provides a broad framework for
  network management implementations.
• The model is specified by the International
  Organization for Standardization (ISO)

Security
Accounting
Fault
Performance
Configuration
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OSI NM Model

• The OSI network management model divides network
  management into five key areas
• Also known as FCAPS model
• fault, configure, account, performance security
  
• Fault management
• Fault management manages network problems in
  order to keep the network running effectively.
• Configuration management
• Configuration management monitors network and
  system configuration information.

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OSI NM Model (2)

• Accounting management
• Accounting management measures and regulates
  network utilization.
• Performance management
• Performance management maintains internetwork
  performance at acceptable levels.
• Security management
• Security management controls access to network
  resources.

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Fault Management

• Manages network problems to keep the network
  running reliably and efficiently.
• Fault management process involves the following
  steps
• Detecting the problem symptoms.
• Isolating the problem.
• Fixing the problem automatically (if possible) or
  manually.
• Testing the fix on all important subsystems.
• Logging the detection and resolution of the
  problem.

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Fault Management (2)

• Test all major sub-system and record the result
  for future reference
• Common display messages in networking devices
• Green No errors
• Yellow May have problems
• Red in a state of error and is no longer in
  service
• Blue is running but has experience an error
• Orange configuration error
• Gray no information about the device is
  available
• Purple device is being queried or polled

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Configuration Management

• Configuration Management monitors network and
  system configuration information and stores it in
  a configuration management database.
• The maintenance of this database allows network
  administrators to track hardware, software, and
  other network resources

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Configuration Management (2)

• Each network device has a variety of information
  associated with it
• Software version information for the operating
  system, protocol software, or management
  software.
• Hardware version information for the interfaces
  or hardware controllers.
• Contact information indicating who to contact if
  problems with the device arise.
• Location information indicating the physical
  location of the device.

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Configuration Management (3)

• CM Information Associated with a Managed Device

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Accounting Management

• Measures network utilization parameters in order
  to regulate individual and group uses of the
  network.
• Minimizes network problems and maximizes fairness
  of user access to the network because network
  resources can be portioned based on network
  capacity and user needs.

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Account Management (2)

• There are 4 Steps in Account Management
• Measuring the use of all important network
  resources.
• Analyzing the results to determine the current
  usage patterns.
• Setting usage quotas.
• Measuring resource utilization on an ongoing
  basis.

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Performance Management

• Maintains internetwork performance at acceptable
  levels by measuring and managing various network
  performance variables.
• Performance variables include network throughput,
  user response times, line utilization, and
  others.
• Performance management involves three basic
  steps
• Gathering data relating to key performance
  variables.
• Analyzing data to determine the normal (baseline)
  performance levels.
• Determining appropriate performance thresholds
  for each variable so that exceeding these
  thresholds indicates a network problem worthy of
  attention.

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Performance Management (2)
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Performance Management (3)

• Reactive
• when performance becomes unacceptable (that is, a
  user-defined threshold is exceeded), the managed
  device reacts by sending an alert to the network
  management system (NMS).
• Proactive
• simulation is used to project how network growth
  will affect performance metrics. These
  simulations alert administrators to impending
  problems before they affect network users.

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Performance Management (4)

• Reactive PM Components
• The management entity continually monitors
  performance variables in managed devices.
• When a particular performance threshold is
  exceeded, the NMS or the managed device detects
  the problem.
• If the managed device detects the problem, it
  generates an alert and sends it to the NMS.
• The NMS takes an appropriate action, such as
  alerting the network administrator.

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Windows Task Manager
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Security Management

• controls access to network resources, and
  prevents network sabotage (intentional or
  unintentional) and unauthorized access to
  sensitive information.
• aids administrators in creating a secure network
  environment. This includes
• partitioning network resources into authorized
  and unauthorized areas,
• mapping groups of users to those areas, and
• monitoring, policing, and logging user access to
  resources in those areas.

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Summary

• Objective and challenge of Network management
• Network management Archiectures centralized,
  distributed, hierarchical
• Components NM Station, Managed device, protocol
• ISO-OSI model FCAPS
• fault
• configuration
• account
• performance
• security