INSTANT DOWNLOAD WITH ANSWERS
Network+ Guide to Networks 6th Edition by Tamara Dean – Test Bank
Chapter 6: Network Hardware, Switching, and Routing TRUE/FALSE
- In data networks, the task of directing information efficiently to the correct destination is handled by connectivity devices, primarily switches and routers.
ANS: T PTS: 1 REF: 243
- Advances in NIC technology are making this hardware smarter than ever.
ANS: T PTS: 1 REF: 243
- It is best to perform connectivity tests on a computer connected to a live network.
ANS: F PTS: 1 REF: 251
- Bridges are protocol independent.
ANS: T PTS: 1 REF: 255
- Cut-through switches can detect corrupt packets.
ANS: F PTS: 1 REF: 260 MULTIPLE CHOICE
- NICs contain a(n) ____, which transmits and receives data signals.
|a.||keyboard port||c.||data transceiver|
ANS: C PTS: 1 REF: 243
- By far, the most popular expansion board NIC today is one that uses a(n) ____ bus.
ANS: B PTS: 1 REF: 244
- PCIe slots vary depending on the number of ____ they support.
ANS: A PTS: 1 REF: 244
- Buses differ according to their ____.
ANS: C PTS: 1 REF: 244
- CompactFlash is an example of a peripheral device attached to the computer’s ____ bus.
ANS: B PTS: 1 REF: 245
- To install a NIC, you must first install the ____.
ANS: B PTS: 1 REF: 246
- Each time a computer starts up, the device drivers for all its connected peripherals are loaded into ____.
ANS: C PTS: 1 REF: 248
- In general, a steady or blinking green LED, sometimes labeled ____, indicates that the NIC is functional and has a connection to the network.
ANS: A PTS: 1 REF: 251
- In addition to viewing its LEDs and using a loopback plug to test a NIC’s functionality, you can also check a NIC’s connectivity with ____.
|a.||simple commands||c.||special switches|
|b.||special clients||d.||special software|
ANS: A PTS: 1 REF: 252
- A hardware component that can be changed without disrupting operations is known as ____.
ANS: C PTS: 1 REF: 252
- Repeaters operate in the ____ layer of the OSI model.
ANS: A PTS: 1 REF: 254
- At its most primitive, a ____ is a repeater with more than one output port.
ANS: B PTS: 1 REF: 254
- A ____ is a repeater with more than one output port.
ANS: C PTS: 1 REF: 254
- A ____ can interpret physical addressing information.
ANS: D PTS: 1 REF: 255
- Traditional switches operate at the ____ layer of the OSI model.
ANS: B PTS: 1 REF: 256
- Switches can create ____ by grouping a number of ports into a broadcast domain.
ANS: D PTS: 1 REF: 260
- To eliminate the possibility of a broadcast storm, switches and bridges implement the ____.
|a.||RIP (Routing Information Protocol)|
|b.||STP (Spanning Tree Protocol)|
|c.||BGP (Border Gateway Protocol)|
|d.||OSPF (Open Shortest Path First) protocol|
ANS: B PTS: 1 REF: 265
- Switches that operate anywhere between Layer 4 and Layer 7 are also known as ____ switches.
ANS: C PTS: 1 REF: 267
- A ____ is a multiport connectivity device that directs data between nodes on a network.
ANS: C PTS: 1 REF: 267
- ____ routing is a technique in which a network administrator programs a router to use specific paths between nodes.
ANS: A PTS: 1 REF: 269
- ____ are combinations of networking hardware and software that connect two dissimilar kinds of networks.
ANS: C PTS: 1 REF: 274 COMPLETION
- A computer’s ____________________ is the circuit, or signaling pathway, used by the motherboard to transmit data to the computer’s components, including its memory, processor, hard disk, and NIC.
ANS: bus PTS: 1 REF: 244
- A(n) ____________________ NIC is integrated into the motherboard.
ANS: on-board PTS: 1 REF: 246
- A(n) ____________________ is software that enables an attached device to communicate with the computer’s operating system.
ANS:device driverdriver PTS: 1 REF: 248
- On a Linux workstation, a popular utility called ____________________ allows you to view and change NIC settings.
ANS: ethtool PTS: 1 REF: 250
- A router that directs data between nodes on an autonomous LAN (or one owned and operated by a single organization) is known as a(n) ____________________ router.
ANS: interior PTS: 1 REF: 269 MATCHING Match each item with a statement below:
- Has no means to interpret the data they retransmit.
- Holds incoming data and accommodates bursts of traffic.
- Devices that connect two network segments by analyzing incoming frames and making decisions about where to direct them based on each frame’s MAC address.
- A switch running in this mode reads the entire data frame into its memory and checks it for accuracy before transmitting the information.
- Plugs into a port and crosses over the transmit line to the receive line so that outgoing signals can be redirected into the computer for testing.
- A switch running in this mode reads a frame’s header and decides where to forward the data before it receives the entire packet.
- Capable of transferring data at up to 1 Gbps per data path.
- Connectivity device that subdivides a network into smaller logical pieces.
- Logically separate networks within networks.
- ANS: D PTS: 1 REF: 254
- ANS: C PTS: 1 REF: 257
- ANS: E PTS: 1 REF: 254
- ANS: H PTS: 1 REF: 260
- ANS: I PTS: 1 REF: 250-251
- ANS: G PTS: 1 REF: 259
- ANS: A PTS: 1 REF: 244
- ANS: F PTS: 1 REF: 256
- ANS: B PTS: 1 REF: 260
- Describe how a computer’s bus can be expanded to include devices other than those found on the motherboard.
ANS:A computer’s bus can be expanded to include devices other than those found on the motherboard. The motherboard contains expansion slots, or openings with multiple electrical contacts, that allow devices such as NICs, modems, or sound cards to connect to the computer’s expanded bus. The devices are found on a circuit board called an expansion card or expansion board. Inserting an expansion board into an expansion slot establishes an electrical connection between the expansion board and the motherboard. Thus, the device connected to the expansion board becomes connected to the computer’s main circuit and part of its bus. With expansion boards connected to its main circuit, a computer can centrally control the device. PTS: 1 REF: 244
- When selecting a NIC to install, explain what an administrator should do if a motherboard supports more than one kind of expansion slot.
ANS:If a motherboard supports more than one kind of expansion slot, refer to the NIC and PC manufacturers’ guidelines for information on the preferred type of NIC. If possible, you should choose a NIC that matches the most modern bus on the motherboard. Although you may be able to use the older bus and NIC types without any adverse effects, some NICs will not work in an older bus if a faster, newer bus is available on the motherboard. PTS: 1 REF: 244-245
- Define wireless NICS. Include a description of disadvantages associated with their use.
ANS:Wireless NICs, which contain antennas to send and receive signals, can be found for all of the bus types we have discussed. Installation and configuration for wireless NICs is the same as for wired NICs. PTS: 1 REF: 246
- Describe how a bridge translates between two segment types.
ANS:To translate between two segment types, a bridge reads a frame’s destination MAC address and decides to either forward or filter it. If the bridge determines that the destination node is on another segment on the network, it forwards (retransmits) the packet to that segment. If the destination address belongs to the same segment as the source address, the bridge filters (discards) the frame. As nodes transmit data through the bridge, the bridge establishes a filtering database (also known as a forwarding table) of known MAC addresses and their locations on the network. The bridge uses its filtering database to determine whether a packet should be forwarded or filtered. PTS: 1 REF: 255
- Explain why network engineers value VLANs. Include a discussion on reasons for using VLANs.
ANS:Network engineers value VLANs for their flexibility. They can include ports from more than one switch or segment. Any type of end node can belong to one or more VLANs. VLANs can link geographically distant users over a WAN, and they can create small workgroups within LANs. Reasons for using VLANs include:
- Separating groups of users who need special security or network functions
- Isolating connections with heavy or unpredictable traffic patterns
- Identifying groups of devices whose data should be given priority handling
- Containing groups of devices that rely on legacy protocols incompatible with the majority of the network’s traffic
- Separating a very large network into smaller, more manageable subnets.
PTS: 1 REF: 261
- Describe the Routing Information Protocol.
ANS:RIP (Routing Information Protocol), a distance-vector routing protocol, is the oldest routing protocol. RIP factors in only the number of hops between nodes when determining the best path from one point to another. It does not consider network congestion or link speed, for example. RIP is an IGP (Interior Gateway Protocol), which means that it can only route data within an autonomous (internal) network. For example, RIP and other IGPs cannot route packets from a LAN across the Internet to another LAN. PTS: 1 REF: 272
- Describe a distance-vector routing protocol suited to WANs.
ANS:A distance-vector routing protocol suited to WANs is BGP (Border Gateway Protocol). Unlike RIP, BGP communicates using BGP-specific messages that travel between routers over TCP sessions. Using BGP, routers can determine best paths based on many different factors. In addition, network administrators can configure BGP to follow policies that might, for example, avoid a certain router or instruct a group of routers to prefer one particular route over other available routes. BGP is the most complex of the routing protocols mentioned in this chapter. Because it is an EGP (Exterior Gateway Protocol) and can span multiple, autonomous networks, it is the routing protocol of choice for Internet traffic, and it is used by border and exterior routers (but not interior routers). PTS: 1 REF: 272
- Explain hybrid routing protocols. Describe an example.
ANS:Some routing protocols reflect characteristics of both link-state and distance-vector routing protocols and are known as hybrid routing protocols. The most popular example is EIGRP (Enhanced Interior Gateway Routing Protocol). This routing protocol, used on interior or border routers, was developed in the mid-1980s by Cisco Systems. It has a fast convergence time and a low network overhead, and is easier to configure and less CPU-intensive than OSPF. EIGRP also offers the benefits of supporting multiple protocols and limiting unnecessary network traffic between routers. It accommodates very large and heterogeneous networks, but is only supported by Cisco routers. On LANs that use exclusively Cisco routers, EIGRP is generally preferred over OSPF. PTS: 1 REF: 273
- Describe the IS-IS routing protocol.
ANS:IS-IS was originally codified by ISO, which referred to routers as “intermediate systems,” thus the protocol’s name. Unlike OSPF, however, IS-IS, a type of IGP, is designed for use on interior routers only. Also, it differs in that it supports two Layer 3 protocols: IP or an ISO-specific protocol. IS-IS is much less common than OSPF. PTS: 1 REF: 273
- Describe two popular types of gateways.
ANS:E-mail gateway—A gateway that translates messages from one type of e-mail system to another. For example, an e-mail gateway allows networks that use Sendmail mail server software to exchange mail with networks that use Microsoft Exchange Server software. Internet gateway—A gateway that allows and manages access between LANs and the Internet. An Internet gateway can restrict the kind of access LAN users have to the Internet, and vice versa. LAN gateway—A gateway that allows segments of a LAN running different protocols or different network models to communicate with each other. A router, a single port on a router, or even a server may act as a LAN gateway. The LAN gateway category might also include remote access servers that allow dial-up connectivity to a LAN. Voice/data gateway—A gateway that connects the part of a network that handles data traffic with the part of a network that handles voice traffic. Voice applications have drastically different requirements than data applications. For example, before a voice signal can be transmitted over a data network, it needs to be digitized and compressed. When it reaches a voice receiver, such as a telephone, it has to be uncompressed and regenerated as recognizable speech, without delays. All these functions require specialized protocols and processes. A voice/data gateway can translate between these unique network segments and traditional data network segments. Firewall—A gateway that selectively blocks or filters traffic between networks. As with any other type of gateway, firewalls may be devices optimized for performing their tasks or computers installed with software necessary to accomplish those tasks. PTS: 1 REF: 274 Chapter 7:Wide Area Networks TRUE/FALSE
- In a star topology, a single connection failure will halt all traffic between all sites.
ANS: F PTS: 1 REF: 297
- Dial-up ISDN does not convert a computer’s digital signals to analog before transmitting them over the PSTN.
ANS: T PTS: 1 REF: 306
- ATM is a WAN technology that functions in the Data Link layer.
ANS: T PTS: 1 REF: 320
- SONET specifies framing and multiplexing techniques at the Physical layer.
ANS: T PTS: 1 REF: 321
- After SONET, BPL has the best maximum throughput available.
ANS: F PTS: 1 REF: 325 MULTIPLE CHOICE
- WANs typically send data over ____ available communications networks.
ANS: B PTS: 1 REF: 294
- The individual geographic locations connected by a WAN are known as ____.
|a.||WAN sites||c.||network service providers|
|b.||WAN links||d.||central offices|
ANS: B PTS: 1 REF: 294
- Because WAN connections require routers or other Layer 3 devices to connect locations, their links are not capable of carrying ____ protocols.
ANS: D PTS: 1 REF: 294
- On most modern WANs, a ring topology relies on ____ rings to carry data.
ANS: D PTS: 1 REF: 296
- ____ WANs are the most fault-tolerant type of WAN because they provide multiple routes for data to follow between any two points.
ANS: C PTS: 1 REF: 298
- The ____ encompasses the entire telephone system, from the wires that enter homes and businesses to the network centers that connect different regions of a country.
ANS: D PTS: 1 REF: 299-300
- A(n) ____ is the place where a telephone company terminates lines and switches calls between different locations.
ANS: A PTS: 1 REF: 300
- A ____ connection is one in which a user connects her computer, via a modem, to a distant network and stays connected for a finite period of time.
ANS: C PTS: 1 REF: 300
- The portion of the PSTN that connects any residence or business to the nearest CO is known as the ____.
|a.||demarcation point||c.||local loop|
|b.||NIU (Network Interface Unit)||d.||central office|
ANS: C PTS: 1 REF: 302
- ____ means that a telephone company connects residential users to its network with fiber-optic cable.
ANS: D PTS: 1 REF: 302
- ____ is an updated, digital version of X.25 that also relies on packet switching.
ANS: C PTS: 1 REF: 304
- In a process called ____, two 64-Kbps ISDN B channels can be combined to achieve an effective throughput of 128 Kbps.
ANS: D PTS: 1 REF: 306
- A ____ converts digital signals into analog signals for use with ISDN phones and other analog devices.
|a.||terminal adapter||c.||smart jack|
ANS: A PTS: 1 REF: 306-307
- ISDN PRI uses ____ B channels and one 64-Kbps D channel.
ANS: C PTS: 1 REF: 307
- The speed of a T-carrier depends on its ____ level.
ANS: A PTS: 1 REF: 309
- At the customer’s demarcation point, either inside or outside the building, RJ-48 connectors terminate in a ____.
ANS: B PTS: 1 REF: 311
- A ____ aggregates multiple DSL subscriber lines and connects them to the carrier’s CO.
|a.||terminal adapter||c.||smart jack|
ANS: B PTS: 1 REF: 317
- Broadband cable requires many subscribers to share the same local line, thus raising concerns about ____ and actual (versus theoretical) throughput.
ANS: D PTS: 1 REF: 319
- What sets ATM apart from Ethernet is its ____ size.
ANS: D PTS: 1 REF: 320
- SONET’s extraordinary ____ results from its use of a double-ring topology over fiber-optic cable.
ANS: C PTS: 1 REF: 322
- The data rate of a particular SONET ring is indicated by its ____, a rating that is internationally recognized by networking professionals and standards organizations.
|a.||OC (Optical Carrier) level||c.||BRI (Basic Rate Interface)|
|b.||CIR (committed information rate)||d.||DS0 (digital signal, level 0)|
ANS: A PTS: 1 REF: 324 COMPLETION
- ____________________ are connections between network nodes that, although based on potentially disparate physical links, logically appear to be direct, dedicated links between those nodes.
ANS: Virtual circuits PTS: 1 REF: 304
- A(n) ____________________ uses TDM (time division multiplexing) over two wire to divide a single channel into multiple channels.
ANS: T-carrier PTS: 1 REF: 308
- ____________________ encapsulates incoming Ethernet or token ring frames, then converts them into ATM cells for transmission over an ATM network.
ANS:LANE (LAN Emulation)LAN EmulationLANE PTS: 1 REF: 321
- A(n) ____________________ node in synchronous communications recognizes that it should be receiving data by looking at the time on the clock.
ANS: receiving PTS: 1 REF: 322
- A(n) ____________________ combines individual SONET signals on the transmitting end, and another multiplexer separates combined signals on the receiving end.
ANS: multiplexer PTS: 1 REF: 323 MATCHING Match each item with a statement below:
|a.||bus topology WAN||f.||upstream|
|b.||star topology WAN||g.||asymmetrical communications|
|c.||mesh topology WAN||h.||symmetrical technology|
|d.||tiered topology WAN||i.||signal level|
- Contain sites that are connected in star or ring formations are interconnected at different levels, with the interconnection points being organized into layers to form hierarchical groupings.
- Occurs when data travels from the carrier’s switching facility to the customer.
- Contains a single site acting as the central connection point for several other points.
- Occurs when downstream throughput is higher than upstream throughput.
- Refers to the T-carrier’s Physical layer electrical signaling characteristics as defined by ANSI standards in the early 1980s.
- Occurs when data travels from the customer to the carrier’s switching facility.
- Occurs when each site is directly connected to no more than two other sites in a serial fashion.
- Provides equal capacity for data traveling both upstream and downstream.
- Incorporates many directly interconnected sites.
- ANS: D PTS: 1 REF: 298
- ANS: E PTS: 1 REF: 314
- ANS: B PTS: 1 REF: 297
- ANS: G PTS: 1 REF: 314
- ANS: I PTS: 1 REF: 309
- ANS: F PTS: 1 REF: 314
- ANS: A PTS: 1 REF: 295
- ANS: H PTS: 1 REF: 314
- ANS: C PTS: 1 REF: 298
- Describe the fundamental properties WANs and LANs have in common.
ANS:WANs and LANs have several fundamental properties in common. Both are designed to enable communication between clients and hosts for resource sharing. In general, both use the same protocols from Layers 3 and higher of the OSI model. And both networks typically carry digitized data via packet-switched connections. PTS: 1 REF: 294
- Define and describe a PSTN.
ANS:PSTN, which stands for Public Switched Telephone Network, refers to the network of lines and carrier equipment that provides telephone service to most homes and businesses. PSTN may also be called POTS (plain old telephone service). The PSTN encompasses the entire telephone system, from the wires that enter homes and businesses to the network centers that connect different regions of a country. PTS: 1 REF: 299-300
- Describe an important difference between frame relay and X.25.
ANS:An important difference between frame relay and X.25 is that frame relay does not guarantee reliable delivery of data. X.25 checks for errors and, in the case of an error, either corrects the damaged data or retransmits the original data. Frame relay, on the other hand, simply checks for errors. It leaves the error correction up to higher-layer protocols. PTS: 1 REF: 304
- Define a fractional T1 and explain why an organization might implement it.
ANS:A fractional T1 lease allows organizations to use only some of the channels on a T1 line and be charged according to the number of channels they use. Thus, fractional T1 bandwidth can be leased in multiples of 64 Kbps. A fractional T1 is best suited to businesses that expect their traffic to grow and that may require a full T1 eventually, but can’t currently justify leasing a full T1. PTS: 1 REF: 310
- Define the term xDSL and name the better known DSL varieties.
ANS:The term xDSL refers to all DSL varieties, of which at least eight currently exist. The better known DSL varieties include ADSL (Asymmetric DSL), G.Lite (a version of ADSL), HDSL (High Bit-Rate DSL), SDSL (Symmetric or Single-Line DSL), VDSL (Very High Bit-Rate DSL), and SHDSL (Single-Line High Bit-Rate DSL) – the x in xDSL is replaced by the variety name. PTS: 1 REF: 314
- Explain how a cable modem is utilized in broadband cable connections.
ANS:Broadband cable connections require that the customer use a special cable modem, a device that modulates and demodulates signals for transmission and reception via cable wiring. Cable modems operate at the Physical and Data Link layer of the OSI model, and, therefore, do not manipulate higher-layer protocols, such as IP. The cable modem then connects to a customer’s PC via an RJ-45, USB, or wireless interface to a NIC. Alternately, the cable modem could connect to a connectivity device, such as a hub, switch, or router, thereby supplying bandwidth to a LAN rather than to just one computer. It’s also possible to use a device that combines cable modem functionality with a router; this single device can then provide both the broadband cable connection and the capability of sharing the bandwidth between multiple nodes. PTS: 1 REF: 318
- Explain how ATM relies on virtual circuits.
ANS:Like X.25 and frame relay, ATM relies on virtual circuits. On an ATM network, switches determine the optimal path between the sender and receiver, then establish this path before the network transmits data. Because ATM packages data into cells before transmission, each of which travels separately to its destination, ATM is typically considered a packet-switching technology. At the same time, the use of virtual circuits means that ATM provides the main advantage of circuit switching – that is, a point-to-point connection that remains reliably available to the transmission until it completes, making ATM a connection-oriented technology. PTS: 1 REF: 321
- List and describe the key strengths of SONET.
ANS:Its four key strengths are that it can integrate many other WAN technologies, it offers fast data transfer rates, it allows for simple link additions and removals, and it provides a high degree of fault tolerance. PTS: 1 REF: 321-322
- Describe the most important advantage of SONET.
ANS:Perhaps the most important SONET advantage is that it provides interoperability. Before SONET, telecommunications carriers that used different signaling techniques (or even the same technique but different equipment) could not be assured that their networks could communicate. Now, SONET is often used to aggregate multiple T1s, T3s, or ISDN lines. SONET is also used as the underlying technology for ATM transmission. Furthermore, because it can work directly with the different standards used in different countries, SONET has emerged as the best choice for linking WANs between North America, Europe, and Asia. Internationally, SONET is known as SDH (Synchronous Digital Hierarchy). PTS: 1 REF: 322
- Why is SONET technology typically not implemented by small or medium-size businesses?
ANS:SONET technology is typically not implemented by small or medium-sized businesses because of its high cost. PTS: 1 REF: 324