Chapter 10. Fault Tolerance, Disaster Recovery, VLANs, and NAS

OBJECTIVES

This chapter covers the following CompTIA-specified objectives for the “Network Implementation” section of the Network+ exam:

Identify the purpose and characteristics of fault tolerance.

• For a network to be effective as a business tool, it must be available. In the quest for network availability, many technologies are employed so that failure of a specific piece of equipment will not necessarily mean that the network becomes unavailable.

Identify the purpose and characteristics of disaster recovery.

• The old saying goes “…when things go wrong, as they usually will.…” The need for businesses to ensure the availability of the network and the data on it, no matter what the circumstance, is a key consideration in network planning. A network administrator plays a key role in this strategy.

Identify the main characteristics of VLANs.

• VLANs are used in modern networks to create divisions within the networks. Although they are not as widely implemented as some other network technologies, VLANs are deployed in many organizations.

Identify the main characteristics of network attached storage (NAS).

• In recent years, the placement of storage on the network has become a driving force in network planning and implementation. One of the most significant technologies associated with this area of the industry is NAS.

OUTLINE

Introduction

Understanding Fault Tolerance

RAID

RAID 0

RAID 1

RAID 2

RAID 3

RAID 4

RAID 5

RAID 10

Choosing a RAID Level

Hardware and Software RAID

Other Fault-Tolerance Measures

Preparing for Faulty Power Supplies

Having Spare Memory

Preventing Processor Failures

Providing Fault Tolerance for NICs

Using Standby Servers

Server Clustering

Using Uninterruptable Power Supplies

Disaster Recovery

Backup Methods

Full Backups

Incremental Backups

Differential Backups

A Comparison of Backup Methods

Backup Rotation Schedules

Backup Best Practices

VLANs

VLAN Membership

Protocol-Based VLANs

Port-Based VLANs

MAC Address–Based VLANs

Network Storage

Traditional File Server Storage

Network Attached Storage (NAS)

SANs

Chapter Summary

Apply Your Knowledge

STUDY STRATEGIES

• Read the objectives at the beginning of the chapter.

• Study the information in the chapter, paying special attention to the tables, which summarize key information.

• Review the objectives again.

• Answer the exam questions at the end of the chapter and check your results.

• Use the ExamGear test on the CD-ROM that accompanies this book to answer additional exam questions concerning this material.

• Review the notes, tips, and exam tips in this chapter. Make sure you understand the information in the exam tips. If you don't understand the topic referenced in an exam tip, refer to the information in the chapter text and then read the exam tip again.