CCNA Certification All-in-One For Dummies

Silviu Angelescu

• Éditeur: For Dummies
• Année: 2010
• ISBN:
  9780470635926
• Édition: 1
• Sujet: Informatik
• Sous-sujet: Zertifizierungsleitfäden in der Informatik

A complete preparation guide for the entry-level networking CCNA certification

If you're planning to advance your career by taking the all-important Cisco Certified Network Associate (CCNA), this is the study guide you need! Seven minibooks cover all the concepts and topics on which you'll be tested, covering the latest version of the exam.

Each part of the exam is covered thoroughly in its own section, so you can readily find the information you want to study. Plenty of review questions help you prepare, and the companion CD-ROM includes the highly rated Dummies Test Engine so you can test your progress with questions based on exam content.

• The Cisco Certified Network Associate (CCNA) is the entry-level certification for network professionals
• Seven minibooks in this guide cover Secure Device Manager, Virtual Private Networks, IPv6, 2960 Switches, Cisco Network Assistant, Advanced EIGRP and OSPF, and Introduction to Wireless Networks
• Covers the latest version of the exam, including the new voice, security and wireless components added in 2008
• Packed with review questions to help you prepare
• Includes more security and troubleshooting information
• CD-ROM includes the popular Dummies Test Engine, an exclusive, fully customizable test-prep software package that features twice as many sample questions as the previous version

CCNA Certification All-In-One For Dummies is the preparation guide you need to earn your CCNA certification.

Note: CD-ROM/DVD and other supplementary materials are not included as part of eBook file.

Book III

Switching with Cisco Switches

Contents at a Glance

Chapter 1: Introducing Layer 2 Switches

Layer 2 — Data Link Layer Review

Purpose of a Layer 2 Switch

Basic Switch Functions

Managing Port Security

Transmitting Unicast, Multicast, and Broadcast

Chapter 2: Managing a Switch Using Cisco IOS

Best Practice for Using Cisco Switches

Connecting to a Cisco Switch

Cisco Switch Startup Process

Configuring a Cisco Switch

Managing Cisco Switch Authentication

Chapter 3: Controlling Network Traffic with Cisco Switches

Sending to MAC Addresses in Remote Networks

Deciding the Fate of Frames

Switching in Half-Duplex and Full-Duplex Modes

Avoiding Loops with Spanning Tree Protocol (STP)

Chapter 4: Spanning Tree Protocol (STP)

Introducing the Spanning Tree Protocol (STP)

STP Operation Flow

Introducing Cisco Options for STP

Introducing Rapid Spanning Tree Protocol (RSTP)

EtherChannel

Monitoring STP

Chapter 5: Virtual Local Area Networks (VLANs)

Introducing Virtual Local Area Networks (VLANs)

Benefits of VLANs

Managing VLANs

Identifying VLANs

VLAN Trunking

VLAN Trunking Protocol (VTP)

Routing Traffic from One VLAN to Another

Chapter 6: Voice over IP (VoIP)

Introducing Voice over IP (VoIP)

VoIP Requires Quality of Service (QoS)

Cisco IP Phone

Cisco Discovery Protocol (CDP)

Configuring VoIP on Cisco Switches

Chapter 7: Troubleshooting a Switch Using Cisco IOS

Troubleshooting Cisco Switches

Chapter 1: Introducing Layer 2 Switches

Exam Objectives

Describing data link OSI Layer 2 and how it relates to Layer 2 switches

Describing the purpose of a Layer 2 switch

Differentiating a Layer 2 switch from a hub or a bridge

Describing the basic Layer 2 switch functions

Managing Layer 2 switch port security

Describing how a Layer 2 switch handles unicast, multicast, and broadcast transmissions

Describing MAC address table thrashing and broadcast storms

Read this chapter to find out about Layer 2 switches.

Layer 2 — Data Link Layer Review

Layer 2 in the Open Systems Interconnection (OSI) and TCP/IP network models is the data link layer. The data link layer transmits data on the physical medium. The data link layer uses physical addresses assigned to each physical network device in the local network to route data from one physical device to another. These addresses are called Media Access Control (MAC) addresses in TCP/IP. MAC addresses uniquely identify a specific network device, such as a switch or a router, or a network interface card (NIC), in a host device.

The data link layer has the following features:

♦ Receives each packet from the network layer on the sending host

♦ Wraps up the packet in a data frame along with local routing data (the physical MAC address)

♦ Sends the data frame to the physical layer to code an electrical or optical signal

The physical layer transmits the data frame over a wire or over the air (wireless transmission).

On the receiving host, the data link layer does the following:

♦ Unwraps the data frame received

♦ Extracts the packet out of the data frame

♦ Sends the packet up to the network layer

The Ethernet TCP/IP protocol is used at Layer 2 for data link operations. Ethernet, defined by the IEEE 802.X standards, is the TCP/IP protocol that operates at Layer 2 to handle data link functions. Hence, whenever you consider Layer 2 in TCP/IP, you really need to think about Ethernet and physical MAC addresses. Layer 2, the data link layer, is only concerned with local-area networks (LANs). The mission of the data link layer is to handle data frame transmission locally between two devices connected on...