Network+ Guide to Networks, 8th Edition 11-1
Chapter 11
Network Performance and Recovery
At a Glance
Instructor’s Manual Table of Contents
• Overview
• Objectives
• Teaching Tips
• Quick Quizzes
• Class Discussion Topics
• Additional Projects
• Additional Resources
• Key Terms
Network+ Guide to Networks, 8th Edition 11-2
Lecture Notes
Overview
Throughout this text, students have learned about building scalable, reliable networks as well as
selecting the most appropriate hardware, topologies, and services to operate a network. Students
Chapter Objectives
After reading this chapter and completing the exercises, the student will be able to:
• Use appropriate tools to monitor device and network events
• Adjust device configurations to optimize network performance
Teaching Tips
Collecting Network Data
1. Define and describe the term network management.
2. Explain that network management can include:
a. controlling user access to network resources
3. Point out that several disciplines fall under the heading of network management.
4. Explain that ideally, network management accomplishes its goals by helping the
administrator predict problems before they occur.
5. Point out that before a network professional can assess and make predictions about a
Monitoring Tools
1. Define and explain a network monitor. Explain that a similar tool is known as a protocol
2. Use Figure 11-1 to discuss methods to monitor network traffic:
3. Mention that to take advantage of network monitoring and analyzing tools, the network
adapter installed in the machine running the software must support promiscuous mode.
4. Discuss the various places from which a network monitor may be obtained.
5. Point out that all network monitors tend to use similar graphical interfaces.
6. Describe the functions all network monitoring tools can perform.
7. Describe some additional functions that some network monitoring tools can perform.
9. Review some commonly used terms for abnormal data patterns and packets, along with
their characteristics:
a. runts
b. giants
c. jabber
10. Point out that many devices come with embedded event logging tools and will store logs
within their own systems.
System and Event Logs
1. Explain how virtually every condition recognized by an operating system can be
recorded.
2. Introduce the Windows-based system event log and point out that it can be easily viewed
with Event Viewer application.
3. Define and describe the UNIX and Linux system log, known as syslog.
4. Explain that syslog defines two possible roles for computer participating in logging
events:
5. Use Table 11-1 to discuss Linux and UNIX system log locations.
7. Explain why using these logs for fault management requires thoughtful data filtering and
sorting.
SNMP Logs
1. Explain why organizations often use network management software.
2. Use Figure 11-6 to discuss the following entities that are part of a network management
architecture:
a. NMS (network management system) server
3. Define the term polling.
4. Explain how agents use SNMP (Simple Network Management Protocol). Discuss the
different versions of SNMP.
5. Use Figure 11-7 to illustrate the relationship between a network management system and
7. Use Figure 11-8 to illustrate a map showing network status.
8. Explain the benefit and drawback of network management applications.
9. Explain why it is important to collect only useful data and not an excessive amount of
routine information.
Performance Baselines
1. Define and explain the term baseline.
2. Explain what might be included in baseline measurements.
3. Use Figure 11-9 to illustrate an example baseline for daily network traffic over a six-
week period.
4. Note that baseline measurements allow a network professional to compare future
6. Describe why network traffic patterns might be difficult to forecast:
7. Explain how a network professional gathers baseline data on the network.
8. Discuss the more common performance metrics used to analyze traffic:
a. utilization
Network+ Guide to Networks, 8th Edition 11-6
Managing Network Traffic
2. Define the term performance management.
Traffic Management
1. Define and describe the term traffic shaping (also called packet shaping).
a. Include an explanation of traffic shaping goals.
3. Use Figure 11-10 to illustrate how traffic volume might appear on an interface without
limits compared to an interface subject to traffic policing.
5. Define and explain traffic prioritization. Discuss some of the characteristics that can be
used to prioritize traffic:
a. Protocol
QoS (Quality of Service) Assurance
1. Define a network’s QoS as group of techniques for adjusting the priority a network
assigns to various types of transmissions.
3. Discuss the two types of forwarding defined by DiffServ:
Network+ Guide to Networks, 8th Edition 11-7
4. Explain that CoS (Class of Service) is sometimes used synonymously with QoS, but there
is a distinction. Discuss that distinction.
5. Mention that a network’s connectivity devices and clients must support the same set of
protocol to achieve their QoS benefits.
Quick Quiz 1
1. True or False: A protocol analyzer is used to monitor traffic at a specific interface
between a server or client and the network.
2. A _____ is a report of the network’s current state of operation.
3. Packets that arrive at their destination but are dropped because issues such as buffer
overflow and latency delayed them from beyond their usable time frame are known as
which type of packet?
a. ghost
b. packet loss
c. discarded packets
d. packet reset
4. Which network management protocol provides for both authentication and encryption?
a. SMTP
b. SNMPv1
c. SNMPv2
d. SNMPv3
5. The calculated percentage of how often bits are damaged is known as which of the
following?
a. error rate
b. utilization
c. packet drops
d. jitter
Network+ Guide to Networks, 8th Edition 11-8
Network Availability
1. Define and explain the term availability.
2. Explain that HA (high availability) refers to a system that functions reliably nearly all the
time.
3. Use Table 11-2 to discuss the importance of measuring a system or network’s availability
vs. downtime. Mention where how this information can be accessed in:
Fault Tolerance
1. Introduce the concept of fault tolerance.
2. Discuss the differences between failures and faults.
3. Introduce students to the following terms:
5. Describe the key to fault tolerance in network design.
6. Explain how to achieve the utmost fault tolerance which will produce a capability known
as automatic failover.
7. Discuss the following concepts:
8. Ensure students understand the function of link aggregation, which is a combination of
9. Use Figure 11-14 to discuss the following advantages to link aggregation:
a. increased total throughput
10. Use Figure 11-15 to demonstrate how link aggregation allows two workstations to
communicate with a server at the same time.
11. Point out that many manufacturers now use LACP (Link Aggregation Control Protocol),
12. Define a load balancer as a device dedicated to the task of distributing traffic intelligently
among multiple computers.
14. Briefly explain the common address redundancy protocol (CARP), which allows a pool
of computers or interfaces to share one or more IP addresses.
15. Use Figure 11-19 to discuss the concept of distributed switching. Point out the following
benefits:
a. centralizes control of VMs
Data Backup and Storage
1. Define the term backup and explain the benefits backups provide.
2. Discuss thing to keep in mind when designing and configuring a backup system.
4. Point out that backing up data is not the same thing as redundancy. Discuss the
differences between data backups and network storage technologies.
6. Describe advantages to using NAS:
a. optimization
7. Discuss the four most common types of RAID:
a. RAID 0
8. Explain that more efficient alternatives have been developed. Discuss one of the
examples, which is block level storage.
9. Introduce the concept of SANs (storage area networks).
10. Describe the following technologies used by SANs:
• FC (Fibre Channel)
11. Use Figure 11-26 to illustrate a SAN using FC connected to a LAN.
12. Use Figure 11-28 to illustrate a SAN using FCoE to connect to a LAN.
13. Explain the installation advantage of SAN.
14. Explain the scalability advantage SAN provides. Point out where the use of SAN is most
appropriate.
Students may read more information on SANs in the IBM Redbook: Introduction
Power Management
1. Explain that part of network management is managing power sources to account for
outages and fluctuations.
3. Discuss the “Applying Concepts: AC and DC Power and Converters” section with your
students. Be sure to define the four types of converters:
4. Describe power flaws that can damage equipment.
a. Surge
5. Explain how network administrators ensure that power remains available and problem
6. Describe the varying characteristics of UPS systems.
7. Discuss the factors to consider when deciding the correct UPS for a network.
a. Amount of power needed
8. Introduce the concept of a generator.
a. Explain characteristics of their use.
10. Use Figure 11-31 to illustrate UPSs and a generator in a network design.
Provide an in-class demonstration by navigating to the APC Web site at
Network+ Guide to Networks, 8th Edition 11–12
Response and Recovery
1. Point out that training and preparation can make all the difference in your company’s
ability to respond and adapt to disasters and security breaches.
Incident Response Policies
1. Explain that incident response policies define the characteristics of an event that qualifies
as a formal incident and steps that should be followed as a result.
2. Give examples of incidents that might qualify as a formal incident, such as:
a. A break-in
3. Describe the six-stage process in incident response:
a. Preparation
4. Point out that the response policy should identify member of a response team and discuss
the suggested team roles:
a. dispatcher
Disaster Recovery Planning
1. Introduce the concept of disaster recovery, which is the process of restoring your critical
2. Mention that the goal of a disaster recovery plan is to ensure business continuity.
3. Discuss sections of a disaster recovery plan relating to computer systems that should be
included.
Disaster Recovery Contingencies
1. Introduce and explain disaster recovery contingency.
2. Use Figure 11-32 to discuss how disaster recovery contingencies are divided into the
following categories:
a. cold site
Data Preservation
1. Explain that data being collected might be presented in a court of law for the purpose of
2. Discuss the steps that should be taken in order to safeguard information until a first
responder or incident response team can take over collection of evidence:
a. Secure the area
b. Document the scene
Quick Quiz 2
1. True or False: An advantage to using NAS is that it can be easily expanded without
interrupting service.
2. What type of power flaw is defined as a momentary increase in voltage due to lightning
strikes, solar flares, or electrical problems?
3. Which of the following is a battery-operated power source directly attached to one or
more devices and to a power supply that prevents undesired features of the wall outlet’s
A/C power from harming the device or interrupting its services?
a. UPS
b. generator
c. transformer
d. SONET
4. True or False. A cold site is a place where the computers, devices, and connectivity
necessary to rebuild a network exist, and all are appropriately configured, updated, and
connected to match a network’s current state.
5. What type of plan accounts for the worst-case scenarios, from a far-reaching hurricane to
a military or terrorist attack?
a. continuity
b. contingency
c. disaster recovery
d. survivability
Class Discussion Topics
1. Ask student to discuss some of the network monitoring tools they have used in their
organization. Ask them to elaborate on any specific issues that were resolved using one
of the network monitoring tools covered in this chapter.
2. Ask students to discuss data backup procedures that are in place at their organization. Do
they have any examples of where having up-to-date backups or another form of
redundancy saved the organization time and money?
Additional Projects
1. Hundreds of network monitoring tools exist. You can purchase or download free network
2. Have the student select and research one topic from the NAS or SAN subject areas. Ask
them to include an analysis of a current commercial or free product implementing the
Network+ Guide to Networks, 8th Edition 11–15
technology. The final report should consist of the following sections: Introduction,
Background and History, Technical Specifications, Implementation, Barriers, and
Summary.
Additional Resources
1. Network Baselining
2. Windows Event Log, Syslog, and SNMP
3. Cisco Traffic Shaping and Policing Overview
4. IBM Storage Area Network (SAN)
5. IBM Redbook: SAN – Redundancy and Resiliency Explained
Key Terms
For definitions of key terms, see the Glossary near the end of the book.
➢ AF (Assured Forwarding)
➢ delay-sensitive
➢ differential backup
➢ DiffServ (Differentiated Services)
➢ disaster
➢ disaster recovery
➢ fault management
➢ fault tolerance
➢ FC (Fibre Channel)
➢ FCoE (Fibre Channel over Ethernet)
➢ first responder
➢ link aggregation
➢ load balancer
➢ load balancing
➢ loss-tolerant
➢ managed object
➢ performance management
➢ polling
➢ port aggregation
➢ QoS (quality of service)
➢ redundancy
➢ redundant power circuit
