CCNP Routing and Switching SWITCH 300-115 Official Cert Guide (2015)


This book focuses on one major goal: to help you prepare to pass the SWITCH exam (300-115). To help you prepare, this book achieves other useful goals as well: It explains a wide range of networking topics, shows how to configure those features on Cisco switches, and explains how to determine whether the features are working. As a result, you can also use this book as a general reference as you work with switched networks in your job. The main motivation for this book and the Cisco Press Certification Guide series is to help you pass the SWITCH exam.

The rest of this introduction focuses on two topics: the SWITCH exam and a description of this book.


Professional certifications have been an important part of the computing industry for many years and will continue to become more important. Many reasons exist for these certifications, but the most popularly cited reason is that of credibility. All other considerations held equal, the certified employee/consultant/job candidate is considered more valuable than one who is not.

Cisco offers four levels of routing and switching certification, each with an increasing level of proficiency: Entry, Associate, Professional, and Expert. These are commonly known by their acronyms CCENT (Cisco Certified Entry Networking Technician), CCNA (Cisco Certified Network Associate), CCNP (Cisco Certified Network Professional), and CCIE (Cisco Certified Internetworking Expert). There are others, too, but this book focuses on the certifications for enterprise networks.

Cisco first announced its initial Professional level certifications in 1998 with the CCNP Routing and Switching certification. To become certified, you must pass exams on a series of CCNP topics, including the SWITCH, ROUTE, and TSHOOT exams. For most exams, Cisco does not publish the scores needed for passing. You need to take the exam to find that out for yourself.

To see the most current requirements for the CCNP Routing and Switching certification, go to, and look for the 300-115 SWITCH exam (Implementing IP Switched Networks, SWITCH v2.0). There you can find out other exam details such as an exam blueprint, which contains a list of exam topics. You will also learn how to register for an exam.

Also, you can go to the Cisco Learning Network website at to find exam information, learning tools, and forums in which you can communicate with others and learn more about this and other Cisco exams.

The SWITCH exam topics are grouped into three broad categories:

Image Layer 2 Technologies

Image Infrastructure Security

Image Infrastructure Services

Table I-1 lists the exam topics, along with the part of this book where the topic is covered. The list of topics is accurate, as of the time this book was printed.


Table I-1 SWITCH Exam 300-115 Topics

How to Take the SWITCH Exam

As of the publication of this book, Cisco exclusively uses testing vendor Pearson Vue ( for delivery of all Cisco career certification exams. To register, go to, establish a login, and register for the 300-115 SWITCH exam. You also need to choose a testing center near your home.

Format of the CCNP SWITCH Exam

The SWITCH exam follows the same general format as the other Cisco exams. When you get to the testing center and check in, the proctor will give you some general instructions and then take you into a quiet room with a PC. When you’re at the PC, you have a few things to do before the timer starts on your exam. For instance, you can take a sample quiz, just to get accustomed to the PC and to the testing engine.

When you start the exam, you will be asked a series of questions. Answer a question, and then move on to the next question. The exam engine does not let you go back and change the answers you entered on previous questions.

The exam questions can be in any of the following formats:

Image Multiple choice (MC)

Image Testlet

Image Drag-and-drop (DND)

Image Simulated lab (sim)

Image Simlet

The first three types of questions are relatively common in many testing environments. The MC format simply requires that you point and click on a circle (that is, a radio button) beside the correct answer for a single-answer question or on squares (that is, check boxes) beside the correct answers for a multi-answer question. Cisco traditionally tells you how many answers you need to choose, and the testing software prevents you from choosing too many answers. Testlets are questions with one general scenario, with multiple MC questions about the overall scenario. DND questions require you to left-click and hold a mouse button, move an object (for example, a text box) to another area on the screen, and release the mouse button to place the object somewhere else-typically into a list. For some questions, as an example, you might need to put a list of five things into the proper order to get the whole question correct.

The last two types both use a network simulator to ask questions. Interestingly, the two types actually allow Cisco to assess two very different skills. First, sim questions generally describe a problem, and your task is to configure one or more routers/switches to fix the problem. The exam then grades the question based on the configuration you changed or added. The simlet questions may well be the most difficult style of question on the exams. Simlet questions also use a network simulator, but instead of answering the question by changing the configuration, the question includes one or more multiple choice questions. The questions require that you use the simulator to examine the current behavior of a network, interpreting the output of any show commands that you can remember to answer the question. Although sim questions require you to troubleshoot problems related to a configuration, simlets require you to both analyze working networks and networks with problems, correlating show command output with your knowledge of networking theory and configuration commands.

The Cisco Learning Network ( website has tools that let you experience the environment and see how each of these question types work. The environment should be the same as when you passed CCNA (a prerequisite for CCNP and CCDP).

CCNP SWITCH 300-115 Official Certification Guide

The most important and somewhat obvious objective of this book is to help you pass the Cisco CCNP SWITCH exam (Exam 300-115). While you are learning about topics that can help you pass the SWITCH exam, you will also become much more knowledgeable about how to do your job. Although this book and the accompanying CD have many exam preparation tasks and example test questions, the method in which they are used is not to simply make you memorize as many questions and answers as you possibly can.

The methodology of this book helps you discover the exam topics about which you need more review, fully understand and remember exam topic details, and prove to yourself that you have retained your knowledge of those topics. So this book helps you pass not by memorization, but by helping you truly learn and understand the topics. The SWITCH exam is just one of the foundation topics in the CCNP Routing and Switching certification, and the knowledge contained within is vitally important to consider yourself a truly skilled routing and switching engineer or specialist.

The strategy you use to prepare for the SWITCH exam might differ slightly from strategies used by other readers, mainly based on the skills, knowledge, and experience you already have obtained. For instance, if you have attended the SWITCH course, you might take a different approach than someone who learned switching through on-the-job training. Regardless of the strategy you use or the background you have, this book is designed to help you get to the point where you can pass the exam with the least amount of time required.

Book Features and Exam Preparation Methods

This book uses several key methodologies to help you discover the exam topics on which you need more review, to help you fully understand and remember those details, and to help you prove to yourself that you have retained your knowledge of those topics.

The book includes many features that provide different ways to study and prepare yourself for the exam. If you understand a topic when you read it, but do not study it any further, you will probably not be ready to pass the exam with confidence. The features included in this book give you tools that help you determine what you know, review what you know, better learn what you don’t know, and be well prepared for the exam. These tools include the following:

Image “Do I Know This Already?” quizzes: Each chapter begins with a quiz that helps you determine the amount of time you need to spend studying that chapter.

Image Foundation topics: These are the core sections of each chapter. They explain the protocols, concepts, and configuration for the topics in that chapter.

Image Exam preparation tasks: The “Exam Preparation Tasks” section lists a series of study activities that should be done after reading the “Foundation Topics” section. Each chapter includes the activities that make the most sense for studying the topics in that chapter. The activities include the following:


Image Key Topics Review: The Key Topic icon is shown next to the most important items in the “Foundation Topics” section of the chapter. The Key Topics Review activity lists the key topics from the chapter, and page number. Although the contents of the entire chapter could be on the exam, you should definitely know the information listed in each key topic. Review these topics carefully.

Image Memory tables: To help you exercise your memory and memorize some lists of facts, many of the more important lists and tables from the chapter are included in a document on the CD. This document lists only partial information, allowing you to complete the table or list. CD-only Appendix C holds the incomplete tables, and Appendix D includes the completed tables from which you can check your work.

Image Definition of key terms: Although Cisco exams might be unlikely to ask a question such as “Define this term,” the SWITCH exam requires that you learn and know a lot of networking terminology. This section lists some of the most important terms from the chapter, asking you to write a short definition and compare your answer to the glossary on the enclosed CD.

Image CD-based practice exam: The companion CD contains an exam engine, including a bank of multiple-choice questions. You can use the practice exams to get a feel for the actual exam content and to gauge your knowledge of switching topics.

How This Book is Organized

Although this book can be read cover to cover, it is designed to be flexible and allow you to easily move between chapters and sections of chapters to focus on specific material. The chapters can be covered in any order, although some chapters are related and build upon each other. If you do intend to read them all, the order in the book is an excellent sequence to use.

This book contains 23 chapters, plus appendixes. The book organizes switching topics into nine major parts. The following list outlines the major part organization of this book.

Image Part IDesigning Campus Networks

Image Chapter 1, “Enterprise Campus Network Design: This chapter covers different campus network models, hierarchical network design, and how to design, size, and scale a campus network using a modular approach.

Image Chapter 2, “Switch Operation: This chapter covers Layer 2 and multilayer switch operation, how various content-addressable memory (CAM) and ternary content-addressable memory (TCAM) tables are used to make switching decisions, and how to monitor these tables to aid in troubleshooting.

Image Chapter 3, “Switch Port Configuration: This chapter covers basic Ethernet concepts, how to use scalable Ethernet, how to connect switches and devices together, and how to verify switch port operation to aid in troubleshooting.

Image Part IIBuilding a Campus Network

Image Chapter 4, “VLANs and Trunks: This chapter covers basic VLAN concepts, how to transport multiple VLANs over single links, how to configure VLAN trunks, and how to verify VLAN and trunk operation.

Image Chapter 5, “VLAN Trunking Protocol: This chapter covers VLAN management using VTP, VTP configuration, traffic management through VTP pruning, and how to verify VTP operation.

Image Part IIIWorking with Redundant Links

Image Chapter 6, “Traditional Spanning Tree Protocol: This chapter covers IEEE 802.1D Spanning Tree Protocol (STP) and gives an overview of the other STP types that might be running on a switch.

Image Chapter 7, “Spanning-Tree Configuration: This chapter covers the STP root bridge, how to customize the STP topology, how to tune STP convergence, redundant link convergence, and how to verify STP operation.

Image Chapter 8, “Protecting the Spanning Tree Protocol Topology: This chapter covers protecting the STP topology using Root Guard, BPDU Guard, and Loop Guard, and also how to use BPDU filtering and how to verify that these STP protection mechanisms are functioning properly.

Image Chapter 9, “Advanced Spanning Tree Protocol: This chapter covers Rapid Spanning Tree Protocol (RSTP) for Rapid PVST+ and Multiple Spanning Tree (MST) Protocol.

Image Chapter 10, “Aggregating Switch Links: This chapter covers switch port aggregation with EtherChannel, EtherChannel negotiation protocols, EtherChannel configuration, and how to verify EtherChannel operation.

Image Part IVMultilayer Switching

Image Chapter 11, “Multilayer Switching: This chapter covers inter-VLAN routing, multilayer switching with Cisco Express Forwarding (CEF), and how to verify that multilayer switching is functioning properly.

Image Chapter 12, “Configuring DHCP: This chapter discusses ways to configure a switch to relay Dynamic Host Configuration Protocol (DHCP) requests or to act as a DHCP server to local client devices.

Image Part VMonitoring Campus Networks

Image Chapter 13, “Logging Switch Activity: This chapter explains how to configure a switch to generate logging information and how to correlate logging messages with accurate timestamps.

Image Chapter 14, “Managing Switches with SNMP: This chapter discusses SNMP and how you can use it to monitor and manage switches in a network.

Image Chapter 15, “Monitoring Performance with IP SLA: This chapter explains how to leverage IP SLA probes to measure network performance against expected service level agreement parameters.

Image Chapter 16, “Using Port Mirroring to Monitor Traffic: This chapter covers methods you can use to mirror or copy switched traffic to a destination where it can be collected and analyzed.

Image Part VIImplementing High Availability

Image Chapter 17, “Understanding High Availability: This chapter discusses ways that multiple physical switches can be connected or configured together to operate as one logical switch, increasing availability.

Image Chapter 18, “Layer 3 High Availability: This chapter covers providing redundant router or gateway addresses on Catalyst switches and verifying that redundancy is functioning properly.

Image Part VIISecuring Switched Networks

Image Chapter 19, “Securing Switch Access: This chapter covers port security using MAC addresses, port-based security using IEEE 802.1X, storm control to reduce traffic storms, and best practices for securing switches.

Image Chapter 20, “Securing VLANs: This chapter covers how to control traffic within a VLAN using access lists, implementing private VLANs, and best practices for securing trunk links.

Image Chapter 21, “Preventing Spoofing Attacks: This chapter explains features like DHCP snooping, IP Source Guard, and dynamic ARP inspection, which you can leverage to prevent network attacks that use spoofed information to gain a foothold.

Image Chapter 22, “Managing Switch Users: This chapter covers switch authentication, authorization, and accounting (AAA)—mechanisms that control who can access a switch and what they can do on the switch, as well as provide a record of what occurred.

Image Part VIIIFinal Preparation

Image Chapter 23, “Final Preparation: This chapter explains how to use the practice exam CD to enhance your study, along with a basic study plan.

Image Part IXAppendixes

Image Appendix A: This appendix contains answers to the “Do I Know This Already” quizzes.

Image Appendix B: This appendix tells you how to find any updates, should there be changes to the exam.

Image Glossary: The glossary contains definitions for all the terms listed in the “Define Key Terms” sections at the conclusions of Chapters 1 through 22.

In addition, you can find the following appendixes on the CD that is included with this book:

Image Appendix C, “Memory Tables: This appendix holds the key tables and lists from each chapter with some of the content removed. You can print this appendix, and as a memory exercise, complete the tables and lists. The goal is to help you memorize facts that can be useful on the exams.

Image Appendix D, “Memory Table Answer Key: This appendix contains the answer key for the exercises in Appendix D.

Image Appendix E, “Study Planner,” is a spreadsheet with major study milestones, where you can track your progress through your study.

Command Syntax Conventions

The conventions used to present command syntax in this book are the same conventions used in the IOS Command Reference. The Command Reference describes these conventions as follows:

Image Boldface indicates commands and keywords that are entered literally as shown. In actual configuration examples and output (not general command syntax), boldface indicates commands that are manually input by the user (such as a show command).

Image Italic indicates arguments for which you supply actual values.

Image Vertical bars (|) separate alternative, mutually exclusive elements.

Image Square brackets ([ ]) indicate an optional element.

Image Braces ({ }) indicate a required choice.

Image Braces within brackets ([{ }]) indicate a required choice within an optional element.