The book's features help you focus on important concepts to succeed in this course: Chapter Objectives -- Review core concepts by answering the focus questions listed at the beginning of each chapter.
Key Terms -- Refer to the lists of networking vocabulary introduced and highlighted in context in each chapter. Glossary -- Consult the comprehensive Glossary with more than terms.
Summary of Activities and Labs -- Maximize your study time with this complete list of all associated practice exercises at the end of each chapter. Check Your Understanding -- Evaluate your readiness with the end-of-chapter questions that match the style of questions you see in the online course quizzes.
The answer key explains each answer. How To -- Look for this icon to study the steps you need to learn to perform certain tasks.
Interactive Activities -- Reinforce your understanding of topics with dozens of exercises from the online course identified throughout the book with this icon. Videos -- Watch the videos embedded within the online course.
The book's features help you focus on important concepts to succeed in this course: Chapter Objectives - Review core concepts by answering the focus questions listed at the beginning of each chapter. Key Terms - Refer to the lists of networking vocabulary introduced and highlighted in context in each chapter.
Glossary - Consult the comprehensive Glossary with more than terms. Summary of Activities and Labs - Maximize your study time with this complete list of all associated practice exercises at the end of each chapter. Routing and switching essentials companion guide To browse Academia. Skip to main content. You're using an out-of-date version of Internet Explorer. By using our site, you agree to our collection of information through the use of cookies.
To learn more, view our Privacy Policy. File Name: routing and switching essentials companion guide pdf download. Routing and Switching Essentials Companion Guide.
Routers are used to segment both collision and broadcast domains. Layer 2 C. Help children know about key characters in the Bible and their stories.
If you still have questions after reading this manual. If the NTP master cannot reach any clock with a lower stratum number, and other systems will be willing to synchronize to it using NTP. The line cards actually contain the ports. The ipv6 route Command 6. Essenitals switch has just been powered on?
Browse more videos. Recipes made with pumpkin pie filling. Star wars audio books canon. Canon d tips and tricks pdf. Leave a Reply Cancel reply Your email address will not be published. Q Notes: These are short sidebars that point out interesting facts, timesaving methods, and important safety issues.
It provides a synopsis of the chapter and serves as a study aid. Q Practice: At the end of chapter there is a full list of all the Labs, Class Activities, and Packet Tracer Activities to refer back to for study time.
Readability The following features have been updated to assist your understanding of the net- working vocabulary: Q Key terms: Each chapter begins with a list of key terms, along with a page- number reference from inside the chapter. The terms are listed in the order in which they are explained in the chapter. This handy reference allows you to find a term, flip to the page where the term appears, and see the term used in con- text.
The Glossary defines all the key terms. Q Glossary: This book contains an all-new Glossary with almost terms. Practice Practice makes perfect. This new Companion Guide offers you ample opportunities to put what you learn into practice.
You will find the following features valuable and effective in reinforcing the instruction that you receive: Q Check Your Understanding questions and answer key: Updated review ques- tions are presented at the end of each chapter as a self-assessment tool. Q Labs and activities: Throughout each chapter, you will be directed back to the online course to take advantage of the activities created to reinforce concepts.
Video Q Page references to online course: After headings, you will see, for example, 1. This number refers to the page number in the online course so that you can easily jump to that spot online to view a video, practice an activity, perform a lab, or review a topic. Packet Tracer allows you to create networks, visualize how packets flow in the network, and use basic testing tools to determine whether the network would work. When you see this icon, you can use Packet Tracer with the listed file to perform a task suggested in this book.
The activity files are available in the course. Packet Tracer software is available only through the Cisco Networking Academy website. Ask your instructor for access to Packet Tracer. Chapter 1 examines switch network design models and explains the ben- efits of implementing a switch network based on a hierarchical design. Switch features are also discussed. The chapter also presents IOS commands used to configure a switch with an IP address, mask, default, and gateway for remote access including SSH access.
Hands-on activities include con- figuration and troubleshooting of VLANs and trunks. This layer is essentially the equivalent of the OSI data link layer and the physical layer.
The chapter discusses how this layer prepares network layer packets for transmission, controls access to the physical media, and transports the data across various media. This chapter includes a description of the encapsulation protocols and processes that occur as data travels across the LAN and the WAN as well as the media used. Explores the concept of a Layer 3 routed port. Includes configuration of inter-VLAN routing using mul- tiple interfaces, router-on-a-stick, and a Layer 3 switch. Issues related to routing between VLANs are also discussed.
The important routing concepts related to addressing, path determination, and data packets for both IPv4 and IPv6 will be presented. The chapter also introduces the construction of a router and the basic router configuration. It explores how TCP uses segmentation, the three-way handshake, and expectational acknowledgments to ensure reliable delivery of data. It also examines the best-effort delivery mechanism provided by UDP and describes when this would be preferred over TCP.
It describes how to use the address mask or prefix length to determine the number of subnetworks and hosts in a network. It explores the calculation of valid host addresses and the determination of both subnet and subnet broadcast addresses.
This chapter examines subnet- ting for both IPv4 and IPv6. Advantages, disadvantages, and types of NAT are also covered. Configuration and troubleshooting of the various NAT types is an integral part of the chapter. Q Glossary: The glossary provides you with definitions for all the key terms iden- tified in each chapter.
Q How has the convergence of data, voice, and Q What switch form factors are available? Q What are the two most commonly used Cisco hierarchical design models? Key Terms This chapter uses the following key terms. You can find the definitions in the Glossary. Users now expect instant access to company resources from anywhere and at any time. These resources not only include tradi- tional data but also video and voice.
There is also an increasing need for collabora- tion technologies that allow real-time sharing of resources between multiple remote individuals as though they were at the same physical location. Different devices must seamlessly work together to provide a fast, secure, and reli- able connection between hosts. LAN switches provide the connection point for end users into the enterprise network and are also primarily responsible for the con- trol of information within the LAN environment.
Routers facilitate the movement of information between LANs and are generally unaware of individual hosts. All advanced services depend on the availability of a robust routing and switching infra- structure on which they can build.
This infrastructure must be carefully designed, deployed, and managed to provide a necessary stable platform. This chapter begins an examination of the flow of traffic in a modern network.
It examines some of the current network design models and the way LAN switches build forwarding tables and use the MAC address information to efficiently switch data between hosts. Class Activity 1. Develop a matrix table listing network data types that can be sent and received. Provide five examples. Note For an example of the matrix, see the document prepared for this modeling activity.
Save your work in either hard- or soft-copy format. Be prepared to discuss your matrix and statements in a class discussion. LAN Design 1. Why is this so important? If someone knows how to design some- thing, it means that person knows and understands the components that comprise the object.
The professional would also know what products to buy to expand the network. Converged Networks 1. In this chapter, we explore the first description. Growing Complexity of Networks 1. The ability to access the Internet and the corpo- rate network is no longer confined to physical offices, geographic locations, or time zones. These requirements drive the need to build next-generation networks that are secure, reliable, and highly available.
These next generation networks must not only support current expectations and equipment, but must also be able to integrate legacy platforms. Figure shows some common legacy devices that must often be incorporated into network design. Figure illustrates some of the newer platforms converged networks that help to provide access to the network anytime, anywhere, and on any device. Including data services, a converged network with collaboration support may include features such as the following: Q Call control: Telephone call processing, caller ID, call transfer, hold, and conference Q Voice messaging: Voicemail Q Mobility: Receive important calls wherever you are Q Automated attendant: Serve customers faster by routing calls directly to the right department or individual One of the primary benefits of transitioning to the converged network is that there is just one physical network to install and manage.
This results in substantial savings over the installation and management of separate voice, video, and data networks. Such a converged network solution integrates IT management so that any moves, additions, and changes are completed with an intuitive management interface. A con- verged network solution also provides PC softphone application support, as well as point-to-point video so that users can enjoy personal communications with the same ease of administration and use as a voice call.
Chapter 1: Introduction to Switched Networks 5 Figure Network Traffic Convergence The convergence of services onto the network has resulted in an evolution in net- works from a traditional data transport role, to a super-highway for data, voice, and video communication.
This one physical network must be properly designed and implemented to allow the reliable handling of the various types of information that it must carry. A structured design is required to allow management of this complex environment. Play the online video to view a few of the collaboration services in action.
Video 1. Click on the second graphic, and play the video to see how people can work more efficiently with collaboration tools. Borderless Switched Networks 1. One of the more recent developments in network design is illustrated by the Cisco Borderless Network architecture illus- trated in Figure The Cisco Borderless Network is a network architecture that combines several innovations and design considerations to allow organizations to connect anyone, anywhere, anytime, and on any device securely, reliably, and seamlessly.
This archi- tecture is designed to address IT and business challenges, such as supporting the converged network and changing work patterns. It enables different elements, from access switches to wire- less access points, to work together and allow users to access resources from any place at any time, providing optimization, scalability, and security to collaboration and virtualization.
Play the online video to learn more about the evolution of the Cisco Borderless Network. Click on the second graphic and play the video to see how a borderless network affects businesses. Hierarchy in the Borderless Switched Network 1. The borderless switched network must deliver on current requirements and future required services and technologies. Understanding how each principle fits in the context of the others is critical. Designing a borderless switched network in a hierar- chical fashion creates a foundation that allows network designers to overlay security, mobility, and unified communication features.
Two time-tested and proven hierar- chical design frameworks for campus networks are the three-tier layer and the two- tier layer models, as illustrated in Figure Figure Switch Network Design Models The three critical layers within these tiered designs are the access, distribution, and core layers. Each layer can be seen as a well-defined, structured module with spe- cific roles and functions in the campus network. Introducing modularity into the campus hierarchical design further ensures that the campus network remains resilient and flexible enough to provide critical network services.
Modularity also helps to allow for growth and changes that occur over time. Core Distribution Access 1. Traditionally, the primary function of an access layer switch is to pro- vide network access to the user. Access layer switches connect to distribution layer switches, which implement network foundation technologies such as routing, quality of service, and security. To meet network application and end-user demand, the next-generation switch- ing platforms now provide more converged, integrated, and intelligent services to various types of endpoints at the network edge.
Building intelligence into access layer switches allows applications to operate on the network more efficiently and securely. Distribution Layer The distribution layer interfaces between the access layer and the core layer to provide many important functions, including: Q Aggregating large-scale wiring closet networks Q Aggregating Layer 2 broadcast domains and Layer 3 routing boundaries Q Providing intelligent switching, routing, and network access policy functions to access the rest of the network Q Providing high availability through redundant distribution layer switches to the end-user and equal cost paths to the core Q Providing differentiated services to various classes of service applications at the edge of the network Core Layer The core layer is the network backbone.
It connects several layers of the campus network. The core layer serves as the aggregator for all of the other campus blocks and ties the campus together with the rest of the network.
The primary purpose of the core layer is to provide fault isolation and high-speed backbone connectivity. Figure shows a three-tier campus network design for organizations where the access, distribution, and core are each separate layers.
To build a simplified, scalable, cost-effective, and efficient physical cable layout design, the recommendation is to build an extended-star physical network topology from a centralized building loca- tion to all other buildings on the same campus. Chapter 1: Introduction to Switched Networks 9 Figure Three-Tier Campus Network Design In some cases, because of a lack of physical or network scalability restrictions, main- taining a separate distribution and core layer is not required.
In smaller campus loca- tions where there are fewer users accessing the network or in campus sites consisting of a single building, separate core and distribution layers may not be needed. In this scenario, the recommendation is the alternate two-tier campus network design, also known as the collapsed core network design.
Figure shows a two-tier campus network design example for an enterprise cam- pus where the distribution and core layers are collapsed into a single layer. Go to the online course to match the term with the switch characteristic. Interactive Activity 1. Perform the practice activity by matching specific characteristics to one of the three layers of the switch network design model. Switched Networks 1. A network profes- sional today must be well-versed in switches and LAN technology in order to add commonly deployed devices such as PCs, printers, video cameras, phones, copiers, and scanners.
Sharing and accessing network devices is common in both the home and business network. Role of Switched Networks 1. It was not long ago that flat Layer 2 switched networks were the norm. Flat Layer 2 data networks relied on the basic properties of Ethernet and the widespread use of hub repeaters to propagate LAN traffic throughout an organization. As shown in Figure , networks have fundamentally changed to switched LANs in a hierarchical network.
A switched LAN allows more flexibility, traffic management, and addi- tional features, such as: Q Quality of service Q Additional security Q Support for wireless networking and connectivity Q Support for new technologies, such as IP telephony and mobility services Figure shows the hierarchical design used in the borderless switched network. It is important to deploy the appropriate types of switches based on network requirements.
Table highlights some common business considerations when selecting switch equipment. Port density Network switches must support the appropriate number of devices on the network. In addition to PoE considerations, some chassis-based switches support redundant power supplies. Reliability The switch should provide continuous access to the network.
Port speed The speed of the network connection is of primary concern to the end users. Frame buffers The capability of the switch to store frames is important in a network where there may be congested ports to servers or other areas of the network.
Scalability The number of users on a network typically grows over time; therefore, the switch should provide the opportunity for growth. When selecting the type of switch, the network designer must choose between a fixed or a modular configuration, and stackable or non-stackable. Another consider- ation is the thickness of the switch, which is expressed in number of rack units. This is important for switches that are mounted in a rack. For example, the fixed con- figuration switches shown in Figure are all 1 rack unit 1U.
These options are sometimes referred to as switch form factors. The particular model deter- mines the features and options available. For example, a port gigabit fixed switch cannot support additional ports.
There are typically different configuration choices that vary in how many and what types of ports are included with a fixed configura- tion switch. Modular Configuration Switches Modular configuration switches offer more flexibility in their configuration. Mod- ular configuration switches typically come with different sized chassis that allow for the installation of different numbers of modular line cards Figure The line cards actually contain the ports.
The line card fits into the switch chassis the way that expansion cards fit into a PC. The larger the chassis, the more modules it can support. There can be many different chassis sizes to choose from. A modular switch with a port line card supports an additional port line card, to bring the total number of ports up to Figure Modular Configuration Switches Stackable Configuration Switches Stackable configuration switches can be interconnected using a special cable that provides high-bandwidth throughput between the switches Figure Cisco StackWise technology allows the interconnection of up to nine switches.
Switches can be stacked one on top of the other with cables connecting the switches in a daisy chain fashion. The stacked switches effectively operate as a single larger switch.
Stackable switches are desirable where fault tolerance and bandwidth availability are critical and a modular switch is too costly to implement. Stackable switches use a special port for interconnections. Many Cisco stackable switches also support StackPower technology, which enables power sharing among stack members. The Switched Environment 1. Learning how switches operate is important to someone enter- ing the networking profession.
Frame Forwarding 1. Switches receive a frame from the source device and quickly forward it toward the destination device. Switching as a General Concept in Networking and Telecommunications 1. The fundamental concept of switching refers to a device making a decision based on two criteria: Q Ingress port Q Destination address The decision on how a switch forwards traffic is made in relation to the flow of that traffic. The term ingress is used to describe a frame entering a device on a specific port.
The term egress is used to describe frames leaving the device through a par- ticular port. When a switch makes a decision, it is based on the ingress port and the destination address of the message. A LAN switch maintains a table that it uses to determine how to forward traffic through the switch. Click the Play button to begin. In the animated example: Q If a message enters switch port 1 and has a destination address of EA, then the switch forwards the traffic out port 4.
Q If a message enters switch port 5 and has a destination address of EE, then the switch forwards the traffic out port 1. Q If a message enters switch port 3 and has a destination address of AB, then the switch forwards the traffic out port 6. The only intelligence of the LAN switch is its capability to use its table to forward traffic based on the ingress port and the destination address of a message.
With a LAN switch, there is only one master switching table that describes a strict associa- tion between addresses and ports; therefore, a message with a given destination address always exits the same egress port, regardless of the ingress port it enters. For a switch to know which port to use to transmit a frame, it must first learn which devices exist on each port.
As the switch learns the relationship of ports to devices, it builds a table called a MAC address table, or content addressable memory CAM table.
CAM is a special type of memory used in high-speed search- ing applications. The switch uses the informa- tion in the MAC address table to send frames destined for a specific device out the port, which has been assigned to that device.
To forward the frame, the switch examines the destination MAC address and com- pares it to addresses found in the MAC address table. If the address is in the table, the frame is forwarded out the port associated with the MAC address in the table. When the destination MAC address is not found in the MAC address table, the switch forwards the frame out of all ports flooding except for the ingress port of the frame.
In networks with multiple interconnected switches, the MAC address table contains multiple MAC addresses for a single port connected to the other switches. The following steps describe the process of building the MAC address table: Step 1. The switch receives a frame from PC 1 on Port 1 Figure Q If the MAC address table already has an entry for that source address, it resets the aging timer.
An entry for a MAC address is typically kept for five minutes. After the switch has recorded the source address information, the switch examines the destination MAC address. The switch enters the source MAC address of PC 3 and the port number of the ingress port into the address table.
The destination address of the frame and its associated egress port is found in the MAC address table Figure The switch can now forward frames between these source and destination devices without flooding because it has entries in the address table that identify the associated ports Figure Ethernet bridges an early version of a switch were added to networks to limit the size of the collision domains.
In the s, advancements in integrated circuit technologies allowed for LAN switches to replace Ethernet bridges. ASICs reduce the packet-handling time within the device, and allow the device to handle an increased number of ports without degrading performance. This method of forward- ing data frames at Layer 2 was referred to as store-and-forward switching. This term distinguished it from cut-through switching.
As shown in the online video, the store-and-forward method makes a forward- ing decision on a frame after it has received the entire frame and then checked the frame for errors. By contrast, the cut-through switching method, as shown in the online video, begins the forwarding process after the destination MAC address of an incoming frame and the egress port has been determined. Click on the second graphic to see an animation of how a cut-through switch works.
Store-and-Forward Switching 1. Error Checking A switch using store-and-forward switching performs an error check on an incoming frame. After receiving the entire frame on the ingress port, as shown in Figure , the switch compares the frame-check-sequence FCS value in the last field of the datagram against its own FCS calculations. The FCS is an error checking process that helps to ensure that the frame is free of physical and data-link errors.
If the frame is error-free, the switch forwards the frame. Otherwise, the frame is dropped. Figure Store-and-Forward Switching Automatic Buffering The ingress port buffering process used by store-and-forward switches provides the flexibility to support any mix of Ethernet speeds.
A store-and-forward switch drops frames that do not pass the FCS check, therefore it does not forward invalid frames. By contrast, a cut-through switch may forward invalid frames because no FCS check is performed. Cut-Through Switching 1. There are two primary characteristics of cut-through switching: rapid frame forwarding and invalid frame processing.
Rapid Frame Forwarding As indicated in Figure , a switch using the cut-through method can make a for- warding decision as soon as it has looked up the destination MAC address of the frame in its MAC address table. The switch does not have to wait for the rest of the frame to enter the ingress port before making its forwarding decision.
For example, the switch can analyze past the first 14 bytes the source MAC address, destination MAC, and the EtherType fields , and examine an additional 40 bytes in order to perform more sophisticated functions relative to IPv4 Layers 3 and 4.
Frames with errors are forwarded to other segments of the network. If there is a high error rate invalid frames in the network, cut-through switching can have a negative impact on bandwidth; thus, clogging up bandwidth with damaged and invalid frames.
Fragment Free Fragment free switching is a modified form of cut-through switching in which the switch waits for the collision window 64 bytes to pass before forwarding the frame. This means each frame will be checked into the data field to make sure no fragmentation has occurred. Fragment free mode provides better error checking than cut-through, with practically no increase in latency.
With a lower latency speed advantage of cut-through switching, it is more appropri- ate for extremely demanding, high-performance computing HPC applications that require process-to-process latencies of 10 microseconds or less. Use the online curriculum to check your answer. Graphic Go to the course outline to perform this practice activity where you have multiple scenarios of frames going through a switch. Select how the switch will handle the frame. Switching Domains 1.
This section tries to explain these two important concepts that affect LAN performance. Collision Domains 1. The network segments that share the same bandwidth between devices are known as collision domains, because when two or more devices within that segment try to communicate at the same time, colli- sions may occur. Chapter 1: Introduction to Switched Networks 23 It is possible, however, to use networking devices such as switches, which oper- ate at the data link layer of the OSI model to divide a network into segments and reduce the number of devices that compete for bandwidth.
Each port on a switch is a new segment because the devices plugged into the ports do not compete with each other for bandwidth. The result is that each port represents a new collision domain. More bandwidth is available to the devices on a segment, and collisions in one collision domain do not interfere with the other segments.
This is also known as microsegmentation. As shown in the Figure , each switch port connects to a single PC or server, and each switch port represents a separate collision domain.
Figure Collision Domains Broadcast Domains 1. For other switches on the LAN to receive broadcast frames, switches must flood these frames out all ports. A collection of interconnected switches forms a single broadcast domain. A network layer device, such as a router, can divide a Layer 2 broadcast domain. Routers are used to segment both collision and broadcast domains. When a device sends a Layer 2 broadcast, the destination MAC address in the frame is set to all binary ones.
A frame with a destination MAC address of all binary ones is received by all devices in the broadcast domain. Watch how a switch broadcasts a frame out all ports except the port that received the frame. When a switch receives a broadcast frame, the switch forwards the frame out each of the switch ports, except the ingress port where the broadcast frame was received. Each device connected to the switch receives a copy of the broadcast frame and processes it, as shown in the top broadcast domain in Figure Broadcasts are sometimes necessary for initially locating other devices and network services, but they also reduce network efficiency.
Network bandwidth is used to propagate the broadcast traffic. Too many broadcasts and a heavy traffic load on a network can result in congestion: a slowdown in the network performance. Figure Broadcast Domains When two switches are connected together, the broadcast domain is increased, as seen in the second bottom broadcast domain shown in Figure In this case, a broadcast frame is forwarded to all connected ports on switch S1.
Switch S1 is con- nected to switch S2. The frame is then also propagated to all devices connected to switch S2. First, they allow the segmentation of a LAN into separate col- lision domains. Each port of the switch represents a separate collision domain and provides the full bandwidth to the device or devices that are connected to that port. Second, they provide full-duplex communication between devices.
A full-duplex connection can carry transmitted and received signals at the same time. Switches interconnect LAN segments collision domains , use a table of MAC addresses to determine the segment to which the frame is to be sent, and can lessen or eliminate collisions entirely. Table shows some important characteristics of switches that contribute to alleviating network congestion.
Table Switch Characteristics That Help with Congestion Characteristic Explanation High port density Switches have high-port densities: and port switches are often just 1 rack unit 1. Large enterprise switches may support hundreds of ports.
Large frame buffers The ability to store more received frames before having to start dropping them is useful, particularly when there may be congested ports to servers or other parts of the network. Port speed Depending on the cost of a switch, it may be possible to support a mixture of speeds. Fast internal switching Having fast internal forwarding capabilities allows high performance.
The method that is used may be a fast internal bus or shared memory, which affects the overall performance of the switch. Low per-port cost Switches provide high-port density at a lower cost.
For this reason, LAN switches can accommodate network designs featuring fewer users per segment, therefore, increasing the average available bandwidth per user. On each graphic, draw a circle around the devices that make up each broadcast or collision domain as directed.
Internet connectivity is not required in this design. All intermediary devices should be labeled with the switch model or name and the router model or name. Save your work and be ready to justify your device decisions and layout to your instructor and the class.
This Syntax Checker activity reviews basic switch con- figurations from the first course. Go to the course outline to perform this practice activity. Packet Tracer Activity 1. Your tasks include configuring initial settings on two switches using the Cisco IOS and configuring IP address parameters on host devices to provide end-to-end connectivity.
Chapter 1: Introduction to Switched Networks 27 We have seen that the trend in networks is toward convergence using a single set of wires and devices to handle voice, video, and data transmission. In addition, there has been a dramatic shift in the way businesses operate. No longer are employees constrained to physical offices or by geographic boundaries. Resources must now be seamlessly available anytime and anywhere. The Cisco Borderless Network archi- tecture enables different elements, from access switches to wireless access points, to work together and allow users to access resources from any place at any time.
The traditional three-layer hierarchical design model divides the network into core, distribution, and access layers, and allows each portion of the network to be opti- mized for specific functionality. It provides modularity, resiliency, and flexibility, which provides a foundation that allows network designers to overlay security, mobility, and unified communication features. In some networks, having a separate core and distribution layer is not required. In these networks, the functionality of the core layer and the distribution layer are often collapsed together.
If the destination MAC address is contained in this table, the frame is forwarded only to the specific destination port. In cases where the destination MAC address is not found in the MAC address table, the frames are flooded out all ports except the one on which the frame was received.
Switches use either store-and-forward or cut-through switching. Store-and-forward reads the entire frame into a buffer and checks the CRC before forwarding the frame. Cut-through switching only reads the first portion of the frame and starts forwarding it as soon as the destination address is read.
Although this is extremely fast, no error checking is done on the frame before forwarding. Every port on a switch forms a separate collision domain allowing for extremely high-speed full-duplex communication. Switch ports do not block broadcasts, and connecting switches together can extend the size of the broadcast domain often resulting in degraded network performance. Practice The following activities provide practice with the topics introduced in this chapter.
Which three options correctly associate a layer of the hierarchical design model with the function of that layer? Choose three. Core - end device connectivity B. Distribution - aggregation and traffic control C. Access - end device connectivity D. Distribution - high speed backbone E. Access - aggregation of traffic F.
Core - high speed backbone 2. Which hierarchical network design goal is to provide a way for the network to always be accessible? Which two layers of the hierarchical network design model are commonly combined into a single layer in a small-to-medium sized network architecture? Choose two.
What is convergence as it relates to network design? Implementation of an access-distribution-core layer design model for all sites in a corporation B. A centralized point in the network design where all traffic aggregates before transmission to the destination C. The combining of voice and video with traditional network traffic D. Designing a network in such a way that each tier has a specific function and upgrade path 5. What are three benefits of a converged network?
Voice and data support staff are combined. Network design is simplified. Network configuration is simplified. Voice, video, and data traffic use one physical network. Maintenance is simpler than hierarchical networks. Network moves, adds, and changes are simplified. Which two terms are correctly defined?
Internal switching rate - processing capability of a switch that quantifies how much data it can process per second B. Port density - capability to use multiple switch ports concurrently for higher throughput data communication C.
Rack unit - number of ports that can fit in a specific switch D. Cut-through switching - the transmission of a frame after the destination MAC address has been examined and processed E.
Layer 1 B. Layer 2 C. Layer 3 D. Layer 4 8. A switch has just been powered on. PC1 connects to port 1; PC2 connects to port 2. If PC1 sends data to PC2, how will the switch process the frame? The switch forwards the frame to all switch ports including ports 1 and 2. What function is most likely to be provided by a Cisco access layer switch? PoE B. Routing C. Link aggregation D. Fault isolation When the switch receives the data, what will the switch do to pro- cess the frame?
Forward the data out all ports. Chapter 1: Introduction to Switched Networks 31 When the switch receives the data, what will the switch do first to process the frame? Forward the data out all ports except for port 4. Forward the data to port 5. Layer 1 or 2 problem? Q What is the function of the boot loader if Q What steps are required to configure a the operating system is corrupt or missing? Q What are the steps taken to configure a Q What mitigation tools could be used on a Cisco switch with an IP address, subnet Cisco switch to prevent or react to a security mask, and default gateway?
0コメント