A

Figure 2-16 illustrates the process of upgrading Cisco IOS Software. Figure 2-16 Complete Cisco IOS Software Upgrade Process Figure 2-16 Complete Cisco IOS Software Upgrade Process Copy startup-config to running-config The boot process follows this basic litany 1 The router performs a power-on self-test (POST) to discover and verify the hardware. 2 The router loads and runs the bootstrap code from ROM. 3 The router finds the IOS or other software and loads it. 4 The router finds the...

A a

Example 8-15 Access List at Mayberry interface serial 0 ip access-group 44 10 Describe the types of packets that this filter would discard, and specify at what point they would be discarded. 11 Does the access list in Example 8-15 stop packets from getting to Web server Governor Why or why not 12 Referring to Figure 8-8, create and enable access lists so that access to Web server Governor is allowed from hosts at any site and so that no other access to hosts in Raleigh is allowed. 13 Name all...

Comment About Data Links

Because the routers build new data-link headers and trailers, and because the new headers contain data-link addresses, the routers must have some way to decide what data-link addresses to use. An example of how the router determines which data-link address to use is the IP Address Resolution Protocol (ARP) protocol. ARP is used to dynamically learn the data-link address of some IP host. An example specific to TCP IP will be useful to solidify the concepts behind routing. Imagine that PC1 is...

A JL

LOBaseT, using hub, simulates single bus lOBaseT, using hub, simulates single bus The concept of cabling each device to a central hub, with that hub creating the same electrical bus as in the older types of Ethernet, was a core fact of 10BaseT Ethernet. Because hubs continued the concept and physical reality of a single electrical path that is shared by all devices, today we call this shared Ethernet All devices are sharing a single 10-Mbps bus. So, hubs solved some cabling and availability...

Answers to Scenario 102 Frame Relay Configuration

Check your IP and IPX address design against the ones chosen in Table 10-27. Of course, your choices most likely are different. However, you should have one subnet per VC when using only point-to-point subinterfaces. With the original criteria of Routers A, D, and E each using multipoint subinterfaces, these three subinterfaces should have been in the same IP subnet and IPX network. Table 10-27 lists the planned Layer 3 addresses for the configurations using multipoint among these three...

Answers to Scenario 91 Pointto Point Verification

Figure 9-20 is a diagram that matches the configuration. The IP and IPX addresses used on the various router interfaces were one of the tasks for this scenario. Table 9-35 is a completed version of Table 9-33, which was the blank table in which you recorded your answers for this task. Finding all the IP and IPX addresses in Examples 9-11, 9-12, and 9-13 requires some persistence. The best plan of attack is to find all the IP addresses and masks that you can, then find all the IPX network...

Answers to Task 2 for Scenario 112

Assuming the details established in Figure 11-25 for Scenario 11-2, the second task for Scenario 11-2 calls for additional encapsulations. Beatrice is using NetWare's Ethernet_II encapsulation, Floyd is using Ethernet_802.3, Barney is using Ethernet_802.2, and Governor is using Ethernet_SNAP. Hopefully you remembered the encapsulation names used in the IOS the names supplied in the problem statement use the NetWare names. (In real life, a simple question mark when typing the ipx network...

Answers to Task 2 for Scenario

To choose a mask and pick enough subnets to use for the original topology illustrated in Figure 6-44, a review of the longer binary algorithm and shortcut algorithm for deriving subnet numbers is required. To review, subnet numbers have the network number value in the network portion of the subnet numbers and have all binary 0s in the host bits. The bits that vary from subnet to subnet are the subnet bits in other words, you are numbering different subnets in the subnet field. Valid subnets...

Other Cisco Certifications

Cisco has many other certifications as well, as summarized in Table 1-2. Refer to Cisco's Web site at for the latest information. Table 1-2 Additional Cisco Certifications Table 1-2 Additional Cisco Certifications The granddaddy of them all CCIE focused on routing and switching, and is the logical conclusion after getting CCNA and then CCNP. Cisco Certified Internetworking Professional is in concept like CCNP, with a focus on service CCIE, with a focus on service provider-oriented technologies....

Answers to Task 3 for Scenario 114

Task 3 for Scenario 11-4 asks you to create SAP filters that perform the same function as described in Task 2. Task 3 suggests a very simple solution, but the simple solution works only because there are local servers in Charlotte, Nashville, and Boston. First take a look at the solution then read over some comments. Because the local server in each case will be the GNS server for the local clients, respectively, all that is needed is to stop Server 1 and Server 2 SAP information from being...

Answers to the Chapter 3 Do I Know This Already Quiz

1 Name the seven layers of the OSI model. Application (Layer 7), presentation (Layer 6), session (Layer 5), transport (Layer 4), network (Layer 3), data link (Layer 2), and physical (Layer 1). 2 What is the main purpose(s) of Layer 3 The network layer defines logical addressing and routing as a means of delivering data across an entire network. IP and IPX are two examples of Layer 3-equivalent protocols. 3 What is the main purpose(s) of Layer 2 The data link layer defines addressing specific to...

Answers to the Chapter 5 Do I Know This Already Quiz

1 What routing protocol does a transparent bridge use to learn about Layer 3 addressing groupings None. Bridges do not use routing protocols. Transparent bridges do not care about Layer 3 address groupings. Devices on either side of a transparent bridge are in the same Layer 3 group in other words, the same IP subnet or IPX network. 2 What settings are examined by a bridge or switch to determine which should be elected as root of the spanning tree The bridge priority is examined first (the...

Approach

Retention and recall are the two features of human memory most closely related to performance on tests. This exam preparation guide focuses on increasing both retention and recall of the exam topics. The other human characteristic involved in successfully passing the exam is intelligence, but this book does not address that issue Adults' retention is typically less than that of children. For example, it is common for 4-year-olds to pick up basic language skills in a new country faster than...

Basic RIP and IGRP Configuration

Each network command enables RIP or IGRP on a set of interfaces. You must understand the subtleties of the network command, as explained in this section. However, what enables really means in this case is not obvious from the Cisco IOS Software documentation. Also, the parameters for the network command are not intuitive to many people who are new to Cisco IOS configuration commands. Therefore, routing protocol configuration, including the network command, is a likely topic for tricky questions...

Cisco Discovery Protocol

The Cisco Discovery Protocol (CDP) discovers basic information about neighboring routers and switches, without needing to know the passwords for the neighboring devices. CDP supports any LAN, HDLC, Frame Relay, and ATM interface. CDP supports any interface that supports the use of SNAP headers. The router or switch can discover Layer 2 and Layer 3 addressing details of neighboring routers without even configuring that Layer 3 protocol this is because CDP is not dependent on any particular Layer...

Cl n

Example 11-17 Albuquerque Command Output, Scenario 11-1 Albuquerque show ipx interface brief Albuquerque show cdp neighbor detail Platform cisco 2500, Capabilities Router Interface Serial0, Port ID (outgoing port) Cisco Internetwork Operating System Software IOS (tm) 2500 Software (C2500-AINR-L), Version Copyright 1986-1997 by Cisco Systems, Inc. Compiled Mon 29-Dec-97 18 47 by ckralik Platform cisco 2500, Capabilities Router Interface Serial1, Port ID (outgoing port) Cisco Internetwork...

Classes of Networks

RFC 790 defines the IP protocol, including three different sizes of networks. By definition, all addresses in the same network have the same numeric value network portion of the addresses. The rest of the address is called the host portion of the address. Using the post office example, the network part is the ZIP code, and the host part is the street address. Just as a letter-sorting machine three states away from you cares only about the ZIP code on a letter addressed to you, a router three...

Comparison of WAN Options

Networking professionals need to know about many WAN options when designing networks. Certainly, Cisco requires CCNAs to have a solid foundation of the WAN technologies described in this chapter. Cisco also expects CCNAs to be able to compare and contrast these different WAN technologies. This section summarizes many of the concepts found earlier in this chapter, with a focus on comparison. The permanent WAN connectivity options can be categorized into two main groups synchronous serial leased...

Connection Establishment and Termination

TCP connection establishment occurs before any of the other TCP features can begin their work. Connection establishment refers to the process of initializing sequence and acknowledgment fields and agreeing to the port numbers used. Figure 6-13 shows an example of connection establishment flow. Figure 6-13 TCP Connection Establishment SEQ 1450, ACK 201 SYN, ACK, DPORT 1027, SPC> RT 80 This three-way connection-establishment flow must complete before data transfer can begin. The connection...

Contents at a Glance

Chapter 1 All About the Cisco Certified Network Associate Certification 3 Chapter 2 Cisco IOS Software Fundamentals 27 Chapter 3 OSI Reference Model and Layered Communication 79 Chapter 4 LANs, Bridges, and Switches 145 Chapter 5 Intermediate LANs Spanning Tree, VLANs, and Trunking 215 Chapter 6 TCP IP and IP Routing 267 Chapter 7 Routing and Routing Protocols 407 Chapter 8 Understanding Access List Security 489 Chapter 9 WAN Protocols and Design 533 Chapter 10 Frame Relay Concepts and...

Data Link Function 2 Addressing

Cisco requires that CCNAs master the formats and meanings of data link layer and network layer addresses. LANs need addressing because there can be many possible recipients of data that is, there could be more than two devices on the link. LANs behave much like people when you have a meeting with three or more people If you want to say something to someone in particular, you first say that person's name or at least look at him. Or, if you want to tell everyone in the meeting something, you just...

DDR Legacy Concepts and Configuration

You can configure DDR in two ways DDR legacy and DDR dialer profiles. The main difference between the two is that DDR legacy associates dial details with a physical interface, whereas DDR dialer profiles disassociate the dial configuration from a physical interface, allowing a great deal of flexibility. The concepts behind DDR legacy apply to DDR dialer profiles as well, but DDR legacy is a little less detailed. Although it's not overly stated in the course, the DDR coverage in the ICND class...

DDR Step 2 Determining the Subset of the Packets That Trigger the Dialing Process

Together, Steps 1 and 2 of legacy DDR logic determine when the dial is attempted. These combined steps are typically called triggering the dial. In Step 1, a packet is routed out an interface to be dialed, but that packet alone does not necessarily cause the dial to occur. The Cisco IOS Software allows the second step to define a subset of the packets routed in Step 1 to actually cause the route to dial. The logic flow is as shown in Figure 9-14. The choice in Step 2 is simply put like this Is...

DDR Step 3 Dialing Signaling

The dialing router needs additional information before the dial can occur. First, for non-ISDN interfaces, it is necessary to communicate the dial string to the external dialing device. In-band signaling (dialing) must be enabled on these interfaces using the command dialer in-band. This is not necessary on a BRI interface, because it uses the out-of-band D channel for signaling. Table 9-17 summarizes what this command implies on different interfaces. Table 9-17 Effect of the dialer in-band...

Deciding What the Other Subnets

When I wrote the four-step process section for IP subnetting, I had two goals in mind. As I mentioned earlier, you need to answer subnetting questions quickly and confidently on the exam. Network engineers also think about subnetting every day, so it's great to be able to do the math in your head. So far, you have dealt with questions regarding a single subnet. You might also need to address the question What are the other valid subnets of this network The details of answering this question...

Distance Vector Routing Protocol Behavior

CCNAs deal with routing problems on a daily basis. Some of these problems are the result of the logic behind distance vector routing protocols. Understanding what distance vector routing means is to understand how a routing protocol accomplishes the following goals Learning routing information Adding the current best route after one has failed The following list summarizes the behavior of a router that uses the RIP-1 or IGRP distance vector routing protocols Routers add directly connected...

Do I Know This Already Quiz

The purpose of the Do I Know This Already quiz is to help you decide what parts of this chapter to use. If you already intend to read the entire chapter, you do not necessarily need to answer these questions now. This 12-question quiz helps you determine how to spend your limited study time. The quiz is sectioned into three smaller four-question quizlets, which correspond to the three major topic headings in the chapter. Figure 2-1 outlines suggestions on how to spend your time in this chapter...

Electing the Root Discovering Root Ports and Designated Ports

Each bridge begins by claiming to be the root bridge by sending STP messages. STP defines these messages used to exchange information with other bridges, which are called bridge protocol data units (BPDUs). Each bridge begins by sending a BPDU stating the following The root bridge's bridge ID At the beginning of the process, each bridge claims to be root, so this value is the same as the bridge ID of this bridge. An administratively set priority This is the priority of the root bridge. At the...

Error Recovery

Cisco expects CCNAs to be able to distinguish between error detection and error recovery. Any header or trailer with a frame check sequence (FCS) or similar field can be used to detect bit errors in the PDU. The FCS uses some magic math against the contents of the frame, with the result recorded in the FCS field. If the receiving device repeats the same math but gets a different value than what is in the FCS field, there were bit errors in transmission. Error detection uses the FCS to detect...

Error Recovery Reliability

TCP provides for reliable data transfer, which is also called reliability or error recovery, depending on what document you read. To accomplish reliability, TCP numbers data bytes using the sequence and acknowledgment fields in the TCP header. TCP achieves reliability in both directions, using the Sequence Number field of one direction combined with the Acknowledgment Field in the opposite direction. If you remember error recovery from Chapter 3, OSI Reference Model and Layered Communication,...

Examination of RIP and IGRP debug and show Commands

Figure 7-10 Sample Three-Router Network with Subnet 10.1.2.0 Failing Figure 7-10 Sample Three-Router Network with Subnet 10.1.2.0 Failing Example 7-4 RIP Configuration and debugs on Albuquerque received v1 update from 10.1.6.253 on Seriall 10.1.3.0 in 1 hops 10.1.2.0 in 2 hops 10.1.5.0 in 1 hops sending v1 update to 255.255.255.255 via Serial0 (10 (POINT NUMBER 1) subnet subnet subnet sending v1 subnet subnet subnet sending v1 subnet subnet subnet subnet subnet update to 255.255.255.255 via...

Example Layer 3 Address Structures

Each Layer 3 address structure contains at least two parts. One (or more) part at the beginning of the address works like the ZIP code and essentially identifies the grouping. All instances of addresses with the same value in these first bits of the address are considered to be in the same group for example, the same IP subnet or IPX network or AppleTalk cable range. The last part of the address acts as a local address, uniquely identifying that device in that particular group. Table 3-10...

Extended IP Access Lists Example

The first example is basic in order to cover the statements syntax. In this case, Bob is denied access to all FTP servers on R1's Ethernet, and Larry is denied access to Server1's Web server. Figure 8-6 is a reminder of the network topology. In Example 8-6, an access list is created on R1. Example 8-6 shows the configuration on R1. Figure 8-6 Network Diagram for Extended Access List Example 1 Figure 8-6 Network Diagram for Extended Access List Example 1 Example 8-6 R1's Extended Access List...

Fast Ethernet and Gigabit Ethernet

Fast Ethernet and Gigabit Ethernet provide faster Ethernet options. Both have gained widespread acceptance in networks today, with Fast Ethernet most likely being used to the desktop and Gigabit Ethernet being used between networking devices or to servers. Fast Ethernet retains many familiar features of 10-Mbps Ethernet variants. The age-old CSMA CD logic still exists, but it can be disabled for full-duplex point-to-point topologies in which no collisions can occur. A variety of cabling options...

Flow Control

Flow control is the process of controlling the rate at which a computer sends data. Depending on the particular protocol, both the sender and the receiver of the data (as well as any intermediate routers, bridges, or switches) might participate in the process of controlling the flow from sender to receiver. Flow control prevents unnecessary congestion by attempting to send data at a rate that the network can currently accomodate. A sender of data might be sending the data faster than the...

Foundation Summary

The Foundation Summary is a collection of tables and figures that provide a convenient review of many key concepts in this chapter. For those of you already comfortable with the topics in this chapter, this summary could help you recall a few details. For those of you who just read this chapter, this review should help solidify some key facts. For any of you doing your final preparation before the exam, these tables and figures will be a convenient way to review the day before the exam. The...

Foundation Topics Spanning Tree Protocol

1 Describe the operation of the Spanning Tree Protocol and its benefits. In the absence of STP, frames would loop for an indefinite period of time in networks with physically redundant links. STP blocks some ports so that only one active path exists between any pair of LAN segments (collision domains). The result of STP is both good and bad Frames do not loop infinitely, which makes the LAN usable, which is good. However, the network does not actively take advantage of some of the redundant...

Foundation Topics The Cisco IOS Software Command Line Interface

42 Examine router elements (RAM, ROM, CDP, show). 44 Control router passwords, identification, and banner. 45 Identify the main Cisco IOS Software commands for router startup. 46 Log in to a router in both user and privileged modes. 48 Use the context-sensitive help facility. 49 Use the command history and editing features. The majority of Cisco routers run Cisco IOS Software, with its familiar command-line interface (CLI). Some routing cards in other devices also run Cisco IOS Software. For...

HDLC and PPP Configuration

One common task for CCNAs is to enable an appropriate point-to-point data-link protocol. The configuration is straightforward, with LAPB being the exception. Be sure to configure the same WAN data-link protocol on each end of the serial link. Otherwise, the routers will misinterpret the incoming frames, and the link will not work. Tables 9-4 and 9-5 summarize the configuration commands and the show and debug commands used for HDLC and PPP configuration. Table 9-4 PPP and HDLC Configuration...

How This Book Is Organized

This book contains 10 core chapters Chapters 2 through 11. Each chapter covers a subset of the topics on the exam. Along with these core chapters, three other chapters help you succeed on the CCNA exam. Chapter 1 helps you understand how to use this book to efficiently and effectively study for the CCNA exam. Chapter 12 is full of lab scenarios that force you to think about all the topics in the book, which helps you with final preparation. And, if you can get access to some lab gear, read...

How to Best Use This Chapter

By following these steps, you can make better use of your study time Keep your notes and the answers for all your work with this book in one place, for easy reference. Take the Do I Know This Already quiz, and write down your answers. Studies show that retention is significantly increased through writing down facts and concepts, even if you never look at the information again. Use Figure 7-1 to guide you to the next step. Do I Know This Already Quiz Read Related Foundation Topics Subsection

Im New to Internetworking with Cisco I Will Not Be Taking the ICND Course and I Bought the Interconnecting Cisco

If you have no networking experience at all, start with the ICND book. The CCNA exam lists ICND as the main prerequisite course before taking the exam. The Cisco Press ICND book contains the actual ICND course materials, handed over by Cisco to Cisco Press, and then converted into book format. The same figures used in the presentations by instructors are used as the figures in the book, with explanations matching what a senior instructor might say when teaching the course. So, if you use one...

IP Configuration

You can easily configure a Cisco router to forward IP traffic when you know the details covered in this chapter so far. Tables 6-48 and 6-49 summarize many of the most common commands used for IP configuration and verification. Two sample network configurations, with both configuration and exec command output, follow. The Cisco IOS documentation is an excellent reference for additional IP commands the Cisco Press book Interconnecting Cisco Network Devices is an excellent reference, particularly...

IP Naming Commands and Telnet

When using the IOS CLI, you will want to refer to names instead of IP addresses. Particularly for the trace, ping, and telnet commands, the IP address or host name must be supplied. This section describes the use of host names on an IOS-based device. Along the way, some nuances of the use of Telnet are covered. The IOS can use statically configured names as well as refer to one or more DNSs. Example 6-13 shows some names statically configured, with configuration pointing to two different DNSs....

ISDN Configuration

Examples 9-8 and 9-9 show the DDR configuration for the network shown in Figure 9-15. ISDN configuration details have been added. The text following these two examples describes the ISDN commands shown. Example 9-8 Completed SanFrancisco Configuration ip route 172.16.3.0 255.255.255.0 172.16.2.1 ip route 172.16.4.0 255.255.255.0 172.16.2.3 Added usernames for CHAP support username LosAngeles password Clark username GothamCity password Bruce access-list 101 permit tcp any host 172.16.3.1 eq 80...

Issues When Multiple Routes to the Same Subnet Exist

A router might learn one route and then learn a better route. Of course, the better route should replace the higher-metric route when this happens. Figure 7-4 outlines just such a case. Table 7-6 shows Router B's routing table when only one route to 162.11.10.0 is known, before the serial link between B and C comes up. Table 7-7 shows Router B's routing table after the link between B and C comes up, learning about another route to that same subnet. Figure 7-4 Routers A and C Advertising to...

Lab 1 Hints

I searched for console connection on www.cisco.com, and I found this pointer that might be helpful If you do everything right but forget to press Enter, the router or switch will not write anything to the screen. You will not hurt anything by pressing Enter too many times Always try a different console cable and connector, make sure the cables are connected well, and make sure the cable is plugged into the console port, not the auxiliary port. Use the disable and enable commands to move back...

Lab 2 Stepby Step Instructions

Step 1 Connect the console cable between your PC's COM1 port and a switch's console port. Step 2 Bring up your favorite terminal emulator program. If you do not have a favorite, use HyperTerminal, which comes with Microsoft operating systems. Select Start, Programs, Accessories, Communications, HyperTerminal. Step 3 Ignore attempts to make you configure a phone number, but configure terminal characteristics of 9600 bps, 8 bits byte, no parity, and 1 start stop bit. This combination is often...

Lab 6 Stepby Step Instructions

Step 2 Verify that you can ping 172.30.103.2, R2's EthernetO IP address. Likewise, verify that you can Telnet to that same address. Step 3 After you have Telnetted to R2, configure the Web server feature on R2 using the ip http server configuration command. Save your configuration on R2. Step 5 From R1, you can use the telnet command to test whether the Web server on R2 is responding, using a trick. From R1, use the command telnet 172.30.103.2 80. This command uses Telnet, but it tries to...

LAN Addressing

LAN addressing identifies either individual devices or groups of devices on a LAN. On the CCNA exam, you are expected to confidently understand and interpret LAN addresses. Unicast addresses identify a single LAN card. Frames between a pair of LAN stations use a source and destination address field to identify each other. These addresses are called unicast addresses, or individual addresses, because they identify an individual LAN interface card. (The term unicast was chosen mainly for contrast...

List of Labs

Table 13-1 describes the labs in this chapter. Router Command-Line Interface Familiarization The main goal of this lab is to make you familiar with getting around the router CLI. This lab offers you hints, ensuring that you understand the basics. 1900 Series Switch Command-Line Interface Familiarization The main goal of this lab is to make you familiar with getting around the switch CLI. This lab offers you hints, ensuring that you understand the basics. 1900 Series Switch VLANs, Trunks, and...

Managing Configuration and System Files

Commands that are used to manage and control the configuration and system software files are slightly different on the 1900 switch family than on IOS-based routers. One of the reasons for the difference is that the switch does not actually run IOS it has many features similar to IOS, including the IOS CLI, but there are and probably always will be some differences. For example, in Example 4-6, the familiar show version command is used to display uptime and software levels, but it does not show...

MTU and Fragmentation

The maximum transmission unit (MTU) is a concept that implies the largest Layer 3 packet that can be forwarded out an interface. The maximum MTU value allowed is based on the data-link protocol essentially, the maximum size of the data portion of the data-link frame (where the packet is placed) is the maximum setting for the MTU on an interface. The default MTU value on Ethernet and serial interfaces is 1,500. If an interface's MTU is smaller than a packet that must be forwarded, fragmentation...

OSI Data Link Layer Functions

5 Describe data-link and network addresses, and identify key differences between them. 6 Define and describe the function of a MAC address. As a CCNA, you'll need to understand both the abstract concepts about the OSI layers and particular instances of such protocols. This section focuses on more of the abstract concepts. Later chapters provide more details about particular LAN and WAN data-link protocols, as well as their configuration in the IOS. This section examines four different protocols...

OSI Reference Model and Layered Communication

In years past, the need to understand the Open System Interconnection (OSI) reference model for networking grew rapidly. The U.S. government passed laws requiring vendors to support OSI software on their systems if vendors did not offer this support, the government would no longer buy the systems. Several vendors even predicted that the global Internet would evolve toward using the OSI protocols instead of TCP IP. As the century turns, however, OSI has been implemented on a much smaller scale...

Overview of Routing Protocols

Several routing protocols for TCP IP exist. IP's long history and continued popularity have called for the specification and creation of several different competing options. So, classifying IP routing protocols based on their differences is useful and also is a fair topic for exam questions. For the CCNA exam, you must know the terminology and routing protocols discussed here. You must also have a deeper understanding of distance vector protocols, which are described in upcoming sections....

Questions on Scenario

1 If this is all the information that you have, what IOS do you expect will be loaded when the user reloads Nova 2 Examine the following command output in Example 2-10, taken immediately before the user is going to type the reload command. What IOS do you expect will be loaded Example 2-10 show ip route Command Output for Nova Nova show ip route Codes C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA...

RIP and IGRP

To pass the CCNA exam, you need to know the particulars of how RIP and IGRP implement distance vector logic. RIP and IGRP both use distance vector logic, so they are similar in many respects. A couple of major differences exist, however they are explained in the upcoming section. Table 7-12 outlines the features of RIP and IGRP. Table 7-12 RIP and IGRP Feature Comparison Table 7-12 RIP and IGRP Feature Comparison Function of bandwidth and delay (the default). Can include reliability, load, and...

RIP Version

RIP-2, defined by RFC 1723, adds advanced features to RIP-1. Many features are the same Hop count is still used for the metric, it is still a distance vector protocol, and it still uses hold-down timers and route poisoning. Several features have been added. They are listed in Table 7-16. Transmits a subnet mask with the route This feature allows VLSM by passing the mask along with each route so that the subnet Both clear text (RFC-defined) and MD5 encryption (a Cisco-added feature) can be used...

Router Memory Processors and Interfaces

The configuration file contains the configuration commands that you have typed, as well as some configuration commands entered by default by the router. The configuration file can be stored in a variety of places, including two inside a router. The router has a couple of other types of memory as well RAM Sometimes called DRAM for dynamic random-access memory, RAM is used by the router just as it is used by any other computer for working storage. The running or active configuration file is...

Scenario 102 Frame Relay Configuration

Site A is the main site, with PVC connections to the other four sites. Sites D and E also have a PVC between them. Examine Figure 10-22 and perform the following activities. Figure 10-22 Scenario 10-2 Frame Relay Network 1 Plan the IP and IPX addresses to be used. Use Table 10-23 if helpful. Use IP network 168.15.0.0. 2 Using the DLCIs shown in Figure 10-22, create configurations for Routers A, B, and E. Use multipoint subinterfaces for the VCs between...

Scenario 113 IPX Filtering

IPX packet and SAP filtering concepts and configuration are reviewed in this scenario. Sample configurations are supplied first. Your job is to interpret the current access lists and then create new packet access lists and SAP access lists to meet some additional criteria. The details are listed after Figure 11-26 and Examples 11-20 through 11-23. Figure 11-26 Network Diagram for Scenario 11-4 Jane Server 3 George Gary Server 4 Steph Brice Server 5 Laurie Jane Server 3 George Gary Server 4...

Scenario 122 Part A Planning

Your job is to deploy a new network with three sites, as shown in Figure 12-3. The decision to use Frame Relay has already been made, and the products have been chosen. For Part A of this scenario, perform the following tasks 1 Subnet planning has been completed. Before implementation, you are responsible for providing a list for the local LAN administrators defining the IP addresses that they can assign to hosts. Using Table 12-5, derive the subnet numbers and broadcast addresses, and define...

Scenario 122 Part B Configuration

The next step in your job is to deploy the network designed in Scenario 12-2, Part A. Use the solutions to Scenario 12-2, Part A to help you identify IP and IPX addresses and the encapsulations to be used. For Scenario 12-2, Part B, perform the following tasks 1 Configure IP and IPX to be routed. Use IP IGRP and IPX RIP as routing protocols. Use IGRP process-id 1. 2 Use secondary IPX addresses to accommodate the multiple IPX encapsulation types described in Scenario 12-2, Part A. 3 Configure...

Scenario 123 Part B Configuration

The next step in your job is to deploy the network designed in Scenario 12-3, Part A. Use the solutions to Scenario 12-3, Part A to help you identify IP and IPX addresses, access lists, and the encapsulations to be used. For Scenario 12-3, Part B, perform the following tasks 1 Configure IP and IPX to be routed. Use IP IGRP and IPX RIP as routing protocols. Use IGRP process-id 1. 2 Use secondary IPX addresses to accommodate the multiple IPX encapsulation types described in Scenario 12-3, Part A....

Scenario 51 LAN Switch Configuration

Your job is to deploy a new LAN switch at a remote site. Figure 5-17 depicts the network. Perform the activities in the list that follows the diagram. Assume that all basic administrative configuration, as covered in Chapter 4, is complete. Figure 5-17 Scenario 5-1 Intermediate LAN Switch Configuration 1 Choose port numbers to be used for each device, as if you were planning the physical installation. Write down these numbers on the diagram. 2 Place Server 1 and Server 2 in VLANs 1 and 2,...

Scenario 61 IP Addressing and Subnet Calculation

No one trusts you yet, so they will not give you any passwords to the router. Your mentor at your new company has left you at his desk while he goes to a meeting. He has left up a Telnet window, logged in to one router in user mode. In other words, you can issue only user-mode commands. Assuming that you had issued the following commands (see Example 6-20), draw the most specific network diagram that you can. Write the subnet numbers used on each link onto...

Scenario 63 IP Subnet Design with a Class C Network

Your job is to plan yet another network. The topology required includes four sites, one Ethernet at each site, and partially meshed Frame Relay for connectivity, as shown in Figure 6-45. The number of subnets will never grow. Choose a mask that will maximize the number of hosts per subnet. Use network 200.1.1.0. Use Table 6-62 to record your choices, or use a separate piece of paper. Figure 6-45 Scenario 6-3 Network Diagram Figure 6-45 Scenario 6-3 Network Diagram Table 6-62 Scenario 6-3...

Scenario 71 IP Configuration

The network engineering group has provided a list of addresses and a network diagram, as shown in Figure 7-14 and Table 7-27. Figure 7-14 Scenario 7-1 Network Diagram Figure 7-14 Scenario 7-1 Network Diagram Table 7-27 Scenario 7-1 IP Addresses Table 7-27 Scenario 7-1 IP Addresses Serial between Albuquerque and Yosemite Serial between Albuquerque and Seville Assuming the details established in Figure 7-14 and Table 7-27 for Scenario 7-1, complete or answer...

Scenario 72 IP Configuration

The network engineering group has provided a list of addresses and a network diagram, with Frame Relay global DLCIs, as shown in Figure 7-15 and Table 7-28. Scenario 7-2 IP Configuration 2 473 Figure 7-15 Scenario 7-2 Network Diagram DLCI 41 s0 DLCI42 sO J DLCI 43 i 3 Jane Table 7-28 Scenario 7-2 IP Addresses Table 7-28 Scenario 7-2 IP Addresses Table 7-28 Scenario 7-2 IP Addresses (Continued) Table 7-28 Scenario 7-2 IP Addresses (Continued) Assuming the...

Scenario 92 Pointto Point Configuration

Your job is to deploy a new network for an environmental research firm. Two main research sites are in Boston and Atlanta a T1 line has been ordered between them. The field site in Alaska will need occasional access ISDN BRI will be used. Another field site in the rain forest of Podunk has a digital 56 kbps link, but it has bursts of errors because parts of the line are microwave. Figure 9-19 shows the routers and links. Figure 9-19 Scenario 9-2 Environmental Research Network Use two different...

Scenarios Scenario

Given the network in Figure 3-23 and the address table in Table 3-17, perform the tasks that follow. This scenario uses an imaginary Layer 3 addressing structure as a method to review concepts. When in doubt, concentrate on the concepts. Also, the imaginary Layer 3 used in this example is here only to allow you to concentrate on the concepts instead of a particular protocol there is no need to memorize this scheme or expect questions like this on the exam. Figure 3-23 Musketeer Network for...

Solutions to Scenario 123 Part A Planning

The IP subnet design includes the use of mask 255.255.254.0. The same mask is used throughout the network. Therefore, at least 9 host bits are needed, because at least one subnet contains 300 hosts. The IPX network number assignment process is straightforward when you're using multiple encapsulations on the same Ethernet. You simply have to choose two different network numbers one per encapsulation type. Each encapsulation type on the router requires the use of a separate IPX network. The...

Solutions to Scenario 123 Part B Configuration

Examples 12-15 through 12-18 show the configurations for tasks 1, 2, and 3 for Part B of Scenario 3. interface serial0 encapsulation frame-relay interface serial 0.2 point-to-point ip address 170.1.10.1 255.255.254.0 ipx network 10 frame-relay interface-dlci 302 ip access-group 102 in interface serial 0.3 point-to-point ip address 170.1.12.1 255.255.254.0 ipx network 12 frame-relay interface-dlci 303 ip access-group 103 in interface serial 0.4 point-to-point ip address 170.1.14.1 255.255.254.0...

Solutions to Scenario 123 Part C Verification and Questions

The answers to the questions for Scenario 12-3, Part C are as follows 1 The ping command uses the outgoing interface's IP address as the source address in the packet, which in this case is 170.1.12.3. Access lists 102 and 103 check the source and destination IP addresses, looking for the subnets on the Ethernet segments. Therefore, the packet is not matched. Look further in Example 12-21 to see an extended ping with source IP address 170.1.7.3 (R3's E0 IP address), and see that it fails. That's...

Step 1 Identify the Structure of the IP Address

Two tasks must be performed in Step 1. First, the rules that define the three parts of an IP address must be remembered and applied. In other words, you must decide how many of the 32 bits in the address comprise the network, subnet, and host portions of the address. The second task is to remember and apply two easy formulas that tell you how many subnets exist and how many hosts there are per subnet. The first task requires that you remember these three facts The network part of the address is...

Syslog and debug

IOS creates messages when different events occur and, by default, sends them to the console. These messages are called syslog messages. If you have used the console of a router for any length of time, you likely have noticed these messages and when they are frequent, you probably became a little frustrated. The router also generates messages that are treated like syslog messages in response to some troubleshooting tasks that you might perform. The debug command is one of the key diagnostic...

Using Secondary Addresses

As a CCNA, Cisco expects you to be comfortable and familiar with IP address planning issues. One such issue involves what to do when there are no more unassigned IP addresses in a subnet. One alternative solution is to change the mask used on that subnet, making the existing subnet larger. However, changing the mask could cause an overlap. For example, if 10.1.4.0 24 is running out of addresses and you make a change to mask 255.255.254.0 (9 host bits, 23 network subnet bits), an overlap can...

Virtual Circuits

Frame Relay provides significant advantages over simply using point-to-point leased lines. The primary advantage has to do with virtual circuits. Consider Figure 10-4, which is a typical Frame Relay network with three sites. Figure 10-4 Typical Frame Relay Network with Three Sites A virtual circuit is a concept that describes a logical path between two Frame Relay DTEs. The term virtual circuit describes the concept well. It acts like a point-to-point circuit, but physically it is not, so it's...

VLAN Configuration for a Single Switch

If only one switch is in use, there is no real benefit to using VTP. However, VTP is on in server mode by default. Because VTP does not help when using a single switch, the first example shows VTP functions being turned off by enabling VTP transparent mode. The steps taken in this example are listed here 1 Enabling VTP transparent mode 2 Creating the VLAN numbers and names 3 Configuring each port's assigned VLAN First, use the vtp global configuration command to configure VTP transparent mode....

How to Use This Book to Pass the Exam

You can choose between two approaches to using this book. In some respects, the CCNA Exam Certification Guide is really two books one book for each of two recommended ways to approach reading the book. Book 1 guides the reader who is new to CCNA networking topics. If you use this approach, you know that you need to learn about all the topics covered on the exam. Book 2 guides the reader who has already been to a CCNA-oriented class or who is experienced in these same topics. If you take this...

Flow Control Using Windowing

TCP implements flow control by taking advantage of the sequence and acknowledgment fields in the TCP header, along with another field called the Window field. This Window field implies the maximum number of unacknowledged bytes allowed outstanding at any instant in time. The window starts small and then grows until errors occur. The window then slides up and down based on network performance, so it is sometimes called a sliding window. When the window is full, the sender will not send, which...

Answers to Scenario 101 Frame Relay Verification

Figure 10-23 is a diagram that matches the configuration. Figure 10-23 Scenario 10-1 Network Derived from show and debug Commands Figure 10-23 Scenario 10-1 Network Derived from show and debug Commands Discovering the IP addresses and subinterfaces is relatively straightforward. The show commands for most subinterfaces are provided. They list the IP address and mask used. The show cdp neighbor detail commands also mention the IP address of the connected routers. The full IPX addresses are more...

Lab 7 Objectives

When finished with this lab, you will be able to do the following Figure 13-3 Frame Relay Network Used in Lab 7 Step 1 The first several steps of this lab use the direct serial link between R1 and R2 that you were using in earlier labs. So, log in to R1 and R2 and ensure that all ACLs from the previous lab have been disabled. Step 2 On R1, change the encapsulation type on Serial0 to PPP encapsulation. From R1, ping R2's serial IP address. Does it still work Step 3 On R2, change the...

Data Link Function 1 Arbitration

Arbitration is needed only when there are instants in time during which it is not appropriate to send data across the media. It's like trying to get through an intersection in your car when all the traffic signals are out you all want to use the intersection, but you had better use it one at a time The arbitration methods vary greatly, depending on how conserative you are, how big the other cars are, how new or old your car is, and how much you value your own life LANs originally were defined...

TCPIP and IP Routing

The TCP IP suite includes the most important protocols covered on the CCNA exam and the protocols used most often in networks today. This chapter covers the TCP IP protocols, including IP addressing and subnetting. Cisco expects CCNAs not just to know IP addressing and routing, but also to know the concepts behind many other TCP IP protocols. In addition, CCNAs should be able to easily recall the commands used to examine the details of IP processing in a router. Of course, Cisco also requires...

Answers to Scenario 92 Pointto Point Configuration

Examples 9-14 through 9-17 show the configurations. Example 9-14 Boston Configuration for Scenario 9-2 hostname Boston ipx routing 0200.aaaa.aaaa no ip domain-lookup username Alaska password Larry isdn switch-type basic-dms100 interface serial0 encapsulation hdlc ip address 200.1.5.5 255.255.255.252 interface serial1 encapsulation hdlc ip address 200.1.5.9 255.255.255.252 ipx network 203 Example 9-14 Boston Configuration for Scenario 9-2 (Continued) interface bri0 encapsulation ppp isdn spidl...

Data Encapsulation

The term encapsulation describes the process of putting headers and trailers around some data. Encapsulation puts the data in the correct, expected format so that another adjacent layer can provide a service or so that the same layer on another computer knows what needs to be done. For example, I put an envelope around my letter to Mike because that was required by the USPS, which provided me a service. I put Mike's name on the envelope so that the people in our home office would know to whom...

Redirect ICMP Message

ICMP redirect messages provide a very important element in routed IP networks. Many hosts are preconfigured with a default router IP address. When sending packets destined to subnets other than the one to which they are directly connected, these hosts send the packets to their default router. If there is a better local router to which the host should send the packets, an ICMP redirect can be used to tell the host to send the packets to this different router. For example, in Figure 6-22, the PC...

Typical ISDN Configurations

32 State a relevant use and context for ISDN networking. ISDN can be used in many different ways on a Cisco router, but all the possibilities revolve around some basic concepts. The ISDN B channels need to be set up, or dialed. Traffic needs to be directed over those B channels. At some point, the B channels should be taken down. Temporary connections between routers are another typical use of ISDN, both for backup and for occasional connections. Occasional connections might be used by a site...

The Cisco IOS Software Boot Sequence

Cisco routers perform the same types of tasks that a typical computer performs when you power it on or reboot (reload) it. Of course, most of us do not think about these details very often. The router performs some somewhat obvious steps, with one of those being tricky namely, the process of choosing the location of the software to load and use in the router. And that software might not be IOS The boot process follows this basic litany 1 The router performs a power-on self-test (POST) to...

Managing Configuration Files

The CCNA exam requires that you be able to distinguish between the configuration file used at startup and the active, running configuration file. The startup configuration file is in NVRAM the other file, which is in RAM, is the one that the router uses during operation. When the router first comes up, the router copies the stored configuration file from NVRAM into RAM, so the running and startup configuration files are identical at that point. Also, exterior to the router, configuration files...

IPX Configuration

Configuration of IPX and IPX RIP on a Cisco router is relatively straightforward. Hands-on experience is the best way to fully learn the details of configuration. In lieu of that, this section lists commands, provides examples, and points out any tricky features. Tables 11-7 and 11-8 summarize the more popular commands used for IPX configuration and verification. Two configuration samples follow. The Cisco IOS Software documentation serves as an excellent reference for additional IPX commands...

Interaction Between OSI Layers

Imagine a Web browser displaying a Web page that it received from a Web server. Before that happened, the browser somehow interacted with the software implementing other layers of TCP IP on the client computer, causing a request to flow to the server. Likewise, the broswer application somehow communicated with the Web server application, telling the server what Web page the browser wanted to display. A fancy way to describe these two ideas that is interaction between OSI layers. The process of...

Data Link Function 4 Identifying the Encapsulated Data

Finally, the fourth part of a data link identifies the contents of the data field in the frame. Figure 3-13 helps make the usefulness of this feature apparent. Figure 3-13 Multiplexing Using Data Link Type and Protocol Fields When PC1 receives data, does it give the data to the TCP IP software or the NetWare client software Of course, that depends on what is inside the data field. If the data came from the Novell server, PC1 hands the data off to the NetWare client code. If the data comes from...

Default Routes and the ip classless Command

When a router needs to route a packet and there is no route matching that packet's destination in the routing table, the router discards the packet. Default routing lets the router forward the packet to some default next-hop router. Default routing is that simple However, two configuration options for default routing make it a little tricky. Also one other option changes the algorithm of how the router decides whether there is a routing table match, which affects when the default route is used....

Standard IP Access List Configuration

Standard IP access list configuration works much like a simple programming language. The logic is something like this If statement 1 is matched, carry out the action defined in that statement. If it isn't, examine the next statement. If it matches, carry out the action it defines. Continue looping through the list until a statement is matched or until the last statement in the list is not matched. A standard access list is used to match a packet and then take the directed action. Each standard...

Scenario 121 Part C Verification and Questions

The CCNA exam tests you on your memory of the kinds of information you can find in the output of various show commands. Using Examples 12-4, 12-5, and 12-6 as references, answer the questions following the examples. NOTE In the network from which these commands were captured, several administrative settings not mentioned in the scenario were configured. For example, the enable password was configured. Any show running-config commands in the examples in this chapter might have other unrelated...

OSI Layers

The OSI reference model consists of seven layers, each of which can (and typically does) have several sublayers. Cisco requires that CCNAs demonstrate an understanding of each layer as well as the protocols that correspond to each OSI layer. The names of the OSI reference model layers and their main functions are simply good things to memorize. And frankly, if you want to pursue your Cisco certifications beyond CCNA, these names and functional areas will come up continually. You also will need...

All About the Cisco Certified Network Associate Certification

Congratulations You have taken your first step toward becoming a member of the group of network professionals who are Cisco Career Certified. The credibility you gain by becoming a Cisco Certified Network Associate (CCNA) is the first important key step to opening doors for career advancement in networking. In case you have already heard some things about the exam, be forewarned the exam format has changed, as compared with the other Cisco exams, including the old CCNA exam. The latest CCNA...