MIS 3360

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MIS 3360

• Chapter 10
• Network Management

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Figure 10-1 Network Demand Versus Budget Trends
Money/ Demand
User Demand
Budget
Time
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Figure 10-2 Cost Issues

• The Importance of Costs
• Exploding demand
• Slow budget growth
• Falling hardware costs help, but software costs
  fall more slowly, and labor costs sometimes rise
• Carrier fee are usually very significant WAN
  connections
• Select the least expensive technology that will
  fully meet user needs

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Cost Issues Total Cost of Ownership

• Fully configured cost of hardware
• Base price plus necessary options
• Often much higher than base price
• Fully configured cost of software
• Initial installation costs
• Vendor setup costs
• IT and end-user labor

• Ongoing costs
• Upgrades
• Labor costs often exceed all other costs
• Immature products have very high labor costs
• Total cost of ownership (TCO) total of all costs
  over life span

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Figure 10-3 Multiyear Cost Analysis Total Cost
of Ownership (TCO)
Year 1
Year 2
Year 3
Year 4
Total
200,000
15,000
15,000
15,000
Base Hardware
245,000
85,000
9,000
9,000
9,000
Hardware Options
112,000
100,000
10,000
10,000
10,000
Base Software
130,000
50,000
10,000
10,000
10,000
Software Options
80,000
435,000
44,000
44,000
44,000
Technology Subtotal
567,000
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Figure 10-3 Multiyear Cost Analysis Total Cost
of Ownership (TCO)
Year 1
Year 2
Year 3
Year 4
Total
75,000
Planning and Development
75,000
50,000
Implementation
50,000
100,000
75,000
75,000
75,000
Ongoing IT Labor
325,000
50,000
25,000
25,000
25,000
Ongoing User Labor
125,000
275,000
100,000
100,000
100,000
Labor Subtotal
575,000
710,000
144,000
144,000
144,000
Total
1,142,000
Note The total cost of ownership is 1,142,000.
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Figure 10-4 Network Simulation

• Simulation
• Build a model, study its implications
• More economical to simulate network alternatives
  than to build them
• Purposes
• Comparing alternatives to select the best one
• Base case and sensitivity analysis to see what
  will happen if the values of variables were
  varied over a range
• Anticipating problems, such as bottlenecks
• Planning for growth, to anticipate areas where
  more capacity is needed

http//panko.net/
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Figure 10-4 Network Simulation

• What is the existing situation

Net 1
Net 4
Utilization in Peak Hour 95
Net 2
Net 5
Too high!
Net 3
Net 6
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Figure 10-4 Network Simulation

• What-if See the Impact of a Change

Net 1
Net 4
Est. Utilization in Peak Hour 70
Added Router
Added Link
Net 2
Net 5
Net 3
Net 6
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Figure 10-4 Network Simulation

• Before the Simulation, Collect Data
• Data must be good
• Otherwise, GIGO (garbage in, garbage out)
• Collect data on the current network
• Forecast growth

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Figure 10-4 Network Simulation

• The Process (Based on OPNET IT Guru)
• Add nodes to the simulation work area (clients,
  servers, switches, routers, etc.)
• Specify the topology with transmission lines
  (including line speeds)
• Configure the nodes and transmission lines (IP
  Time-to-Live value, etc.)
• Add applications, which generate traffic data

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Figure 10-4 Network Simulation

• The Process
• Run the simulation for some simulated period of
  time
• Examine the output to determine implications
• Validate the simulation (compare with reality if
  possible to see if it is correct)
• What-if analysis
• Application performance analysis (OPNET ACE)

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IP Addresses

• All devices connected to the Internet have a
  32-bit IP address associated with it.
• For example,
• 10000000 10011100 00001110 00000111
• translates to
• 128.156.14.7
• There are basically four types of IP addresses
  Classes A, B, C and D.
• A particular class address has a unique network
  address size and a unique host address size.

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Four basic forms of 32-bit IP addresses
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IP Addresses

• When you examine the first decimal value in the
  dotted decimal notation
• All Class A addresses are in the range 0 -
  127
• All Class B addresses are in the range 128 - 191
• All Class C addresses are in the range 192 - 223

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IP Subnet Masking

• Sometimes you have a large number of IP address
  to manage.
• By using subnet masking, you can break the host
  ID portion of the address into a subnet ID and
  host ID.
• For example, the subnet mask 255.255.255.0
  applied to a class B address will break the host
  ID (normally 16 bits) into an 8-bit subnet ID and
  an 8-bit host ID.

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Network Management Utilities Figure 10-12

• Network management utilities are programs to help
  network managers administer the network
• Security Issues
• Management tools can be used to make attacks
• Policies should limit these tools to certain
  employees and for certain purposes
• Firewalls block many network management tools to
  avoid attacks

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Figure 10-12 Network Management Utilities

• Host Diagnostic Tools
• Network Setup Wizard works most of the time need
  tools if it does not
• Testing the connection
• Open a connection to a website using a browser
• Ping a host to see if latency is acceptable
• Loop-back testing and ipconfig/winipconfig
• Go to the command line
• Ping 127.0.0.1. This is the loop-back interface
  (you ping yourself)

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Network Management Utilities Host Diagnostic
Tools

• Packet capture and display programs
• Capture data on individual packets
• Allows extremely detailed traffic analysis
• Look at individual packet data and summaries
• WinDUMP is a popular packet capture and display
  program on Windows
• Traffic summarization
• Shows statistical data on traffic going into and
  out of the host
• EtherPeek is a popular commercial traffic
  summarization program

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Figure 10-12 Network Management Utilities

• Route Analysis Tools
• To test the route to another host
• Ping tests gives the latency of a whole route
• Tracert gives latencies to router along the path

Ping 275 ms
250 ms
Tracert
25 ms
75 ms
225 ms
150 ms (Problem?)
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Figure 10-12 Network Management Utilities

• Network Mapping Tools
• To understand how the network is organized
• Discovering IP addresses with active devices
• Fingerprinting them to determine their operating
  system (client, server, or router)
• A popular network mapping program is Nmap

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Figure 10-16 Simple Network Management Protocol
(SNMP)

• Simple Network Management Protocol (SNMP)
• Standard for managing remote devices in a network
• Collects information from remote devices to give
  the network administrator an overview of the
  network
• Optionally, allows the network administrator to
  reconfigure remote devices
• Potential for strong labor cost savings

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Figure 10-16 Simple Network Management Protocol
(SNMP)
Network Management Agent (Agent), Objects
Network Management Software (Manager)
Network Management Agent (Agent), Objects
RMON (remote monitoring) probe is a special agent
that collects data about multiple devices in a
region of in the network. It is like a local
manager that can be queried by the main manager.
RMON Probe
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Traffic Management Methods

• Traffic Management
• Capacity is expensive it must be used wisely
• Especially in WANs
• Traditional Approaches
• Overprovisioning
• In Ethernet, install much more capacity than is
  needed most of the time
• This is wasteful of capacity
• Does not require much ongoing management labor

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Traffic Management Methods Traditional Approaches

• Priority
• In Ethernet, assign priority to applications
  based on sensitivity to latency
• In momentary periods of congestion, send
  high-priority frames through
• Substantial ongoing management labor

• QoS Reservations
• In ATM, reserve capacity on each switch and
  transmission line for an application
• Allows strong QoS guarantees for voice traffic
• Highly labor-intensive
• Data gets the scrapscapacity that is not
  reserved for voice

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Figure 10-19 Traffic Management Methods

• Traffic Shaping
• The Concept
• Control traffic coming into the network at access
  switches
• Filter out unwanted applications
• Give a maximum percentage of traffic to other
  applications

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Handling Momentary Traffic Peaks with
Overprovisioning Priority
Congestion and Latency
Traffic
Momentary Traffic Peak Congestion and
Latency Sometimes, Frame Loss
Network Capacity
Time
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Figure 10-19 Traffic Management Methods

• Traffic Shaping
• Advantages and Disadvantages
• Traffic shaping alone reduces traffic coming into
  the network to control costs
• Very highly labor intensive
• Creates political battles (as do priority and QoS
  reservations to a lesser degree)

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Handling Momentary Traffic Peaks with
Overprovisioning Priority, Contd
Overprovisioned Traffic Capacity in Ethernet
Traffic
Overprovisioned Network Capacity
Momentary Peak No Congestion
Time
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Handling Momentary Traffic Peaks with
Overprovisioning Priority, Contd
Priority in Ethernet
Traffic
Momentary Peak
High-Priority Traffic Goes Low-Priority Waits
Network Capacity
Time