Section 11.1• Identify customer requirements• Recommend appropriate network topologies• Gather data about existing equipment and software

Section 11.2• Demonstrate knowledge of RAID levels and how to choose between them• Identify planning strategies for network growth• Describe hardware compatibility issues

Section 11.3• Identify methods to measure server performance• Demonstrate OS performance• Identify methods to measure network performance

11.1pp. 312-319

Main Ideas

Designing a network requires careful planning. Decisions about an existing network should always be made with future growth in mind.

Key Terms

budget

legacy application

patch cable

Guide to Reading

Network Design

11.1pp. 312-319

Customer Requirements

It is important to lay a good foundation as you build a functional network. Throughout this section, we examine a fictional company that hired you to install a computer network. Keep in mind that the choices we make are based on the requirements of this hypothetical company and do not address every company’s networking situation and needs.

Network Design

11.1pp. 312-319

In addition to the customer’s technical requirements for the network, you also have to work within a budget.

Working within the budget often means making difficult decisions regarding all aspects of the network.

budget A summary stating how much money and time will be used toward a specific purpose. (p. 313)

Customer Requirements

Network Design

11.1pp. 312-319

Peer-to-Peer or Client/Server?

The first decision to be made for the new network is whether it should be a peer-to-peer or a client/server network.

The factors we need to examine include the following:

• size of the network

• level of security

• type of business

• level of administrative support available

• amount of network traffic

• needs of the network users

• network budget

Network Design

11.1pp. 312-319

A proper inventory involves at least four categories, including:

• hardware

• software (including legacy applications)

• telecommunications equipment

• network requirements

legacy application Software that may use older technology, which may be considered outdated compared with today’s applications. (p. 316)

Taking Inventory

Network Design

11.1pp. 312-319

Building a Map

Before a plan is recommended, it is a good idea to make a map of all the elements involved.

Consider two aspects of the network:

• the physical layout, including the location of each piece of hardware and how it relates to the others

• the physical and logical topology of the proposed network

Network Design

11.1pp. 312-319

The simplest layout for a network in the small-office environment is to use a physical star.

After the media are installed, connecting the computers is straightforward, using a patch cable.

patch cable A short length of cable with connectors at each end. (p. 318)

Installing Network Media

Network Design

11.1pp. 312-319

Designing Within an Existing Infrastructure

Network installations within existing infrastructure present many challenges:

• cost

• physical factors

• supporting the new infrastructure

Network Design

11.1pp. 312-319

You Try It

• Activity 11A – Surveying Network Hardware (p. 314)• Activity 11B – Inventorying Software (p. 316)• Activity 11C – Determining Network Requirements (p. 317) • Activity 11D – Mapping the Facility (p. 317)

Network Design

11.2pp. 321-324

Main Ideas

Servers make use of RAID hard drive technology to provide faster disk access and better data security. It is important to plan for change when designing a network. Select hardware carefully to ensure it is compatible with existing hardware.

Key Terms

array

striping

mirroring

parity

pilot deployments

Guide to Reading

Selecting Hardware

11.2pp. 321-324

RAID Levels

There are several levels of RAID, each with its own specific capabilities. RAID levels are sometimes combined to provide the capabilities of multiple levels at the same time.

Selecting Hardware

11.2pp. 321-324

RAID 0A technique called striping is used at the RAID 0 level.

RAID 1A technique called mirroring is used at the RAID 1 level.

RAID 3Parity is used at RAID 3.

RAID 5Instead of using a dedicated parity drive, the parity information at the RAID 5 level is distributed among the drives in the array.

striping A RAID 0 level technique that spreads data across each drive in an array. Increases the array’s read and write speeds. (p. 321)

mirroring A process of duplicating data on the primary drive to the other drive(s) in the array. (p. 322)

parity The detecting of errors in information which increases fault tolerance at the RAID 3 level. (p. 322)

RAID Levels

Selecting Hardware

11.2pp. 321-324

RAID Levels

Here is an example of RAID 0 and RAID 1.

Selecting Hardware

11.2pp. 321-324

Scalability and Planning for Change

When a business expands, its networking needs change and scale. Three approaches to consider for scalability are described below:

• A server may require additional RAM or CPUs to keep up with additional users.

• More disk space may be needed to provide more storage space.

• Servers may need to be clustered to meet increased demand.

Selecting Hardware

11.2pp. 321-324

Pilot deployments, also known as test installations, can also make changes easier.

For example, new software may be installed on a few user systems. After a period of testing, the software is installed throughout the network.

pilot deployment A period of testing new software or program changes before installation on a network. Also known as a test installation. (p. 323)

Scalability and Planning for Change

Selecting Hardware

11.2pp. 321-324

Hardware Compatibility

Evaluating and selecting hardware is a major part of planning for network implementation.

The most common incompatibilities occur between hardware and software.

Be certain to address compatibility issues between new software and existing hardware before you start any upgrades.

Selecting Hardware

11.2pp. 321-324

Hardware Compatibility

You should consider the following list when implementing new hardware:

• read the documentation

• verify that devices are detected during installation

• check minimum requirements

Selecting Hardware

11.3pp. 326-332

Main Ideas

Regular monitoring of server performance can help pinpoint potential problems. Monitoring network traffic can be useful when trying to determine the cause of network problems or deliberate attacks.

Key Terms

baseline

network monitor

protocol analyzer

Internet Control Message Protocol (ICMP)

Denial of Service (DoS)

Guide to Reading

Server & Network Performance

11.3pp. 326-332

When the network is first set up, it is very important to create a baseline. This baseline can be used to compare performance over time.

baseline A measurement used for determining statistics. For example, a baseline would help determine a server’s performance and traffic flow over a period of time. (p. 326)

Server Performance

Server & Network Performance

11.3pp. 326-332

Server Performance

The Windows 2000 and XP OSs feature a tool called Performance Monitor.

This tool monitors:

• Processor Time• Interrupt Time• Privileged Time• User Time

Server & Network Performance

11.3pp. 326-332

Network monitors are very useful for establishing part of the network baseline.

After the baseline has been established, it is possible to:

• troubleshoot traffic problems

• monitor network usage to determine when it is time to upgrade

network monitors Software tools, similar to performance monitors, that track all or a selected part of network traffic. (p. 329)

Network Performance

Server & Network Performance

11.3pp. 326-332

Protocol analyzers are the tools used most often to monitor network interactivity.

Network administrators who work with large networks rely heavily on protocol analyzers.

protocol analyzer A tool used to perform real-time network traffic analysis using packet capture, decoding, and transmission data. (p. 330)

Network Performance

Server & Network Performance

11.3pp. 326-332

Network Performance

Windows 2000 Server includes a utility called Network Monitor that allows a network administrator to analyze network traffic. This utility can be used to analyze a number of different network statistics. This information is often critical when trying to isolate potential intrusions.

Server & Network Performance

11.3pp. 326-332

Certain types of hacker attacks use one of the TCP/IP protocols, called Internet Control Message Protocol (ICMP).

It can also be responsible for flooding a network with ICMP messages, creating a Denial of Service (DoS) attack.

Information generated by Network Monitor can help an administrator find the exploited machine and close the security hole.

Internet Control Message Protocol (ICMP) An Internet protocol used to help hosts control network traffic and respond to various error conditions. (p. 332)

Denial of Service (DoS) A type of computer attack that makes it impossible for a receiving computer to function correctly. The attack can cause the recipient to freeze, crash, or reboot, or cause a system to become paralyzed. (p. 332)

Network Performance

Server & Network Performance

11.3pp. 326-332

You Try It

• Activity 11E – Configuring Performance Monitor (p. 327)• Activity 11F – Analyzing the Network Using Network

Monitor (p. 331)

Server & Network Performance

Resources

For more resources on this chapter, go to the Introduction to Networks and Networking Web site at http://networking.glencoe.com.

Chapter 11