Chapter2 Flashcards
Which of the following best describes the function of the network medium?
The network medium provides the physical connection between networked computers.
The network medium provides the protocol used to transmit data between end systems.
The network medium passes data between two routers.
The network medium processes electrical or light signals and converts them to data.
A. The network medium provides the physical connection between networked computers. This connection can be made through a copper-based, fiber-optic, or wireless medium. The network medium is not a protocol, and it does pass data; it only carries signals. The network medium does not process electrical or light pulses and convert them to data; it carries only the signals generated by transceivers.
Which of the following signal types is carried by copper cable? Fiber optic Microwave Infrared Electrical
D. Copper cables use electrical signals to transmit data. Fiber optic is a cable type, not a signal type. Microwave signals can’t be transmitted over copper cable. Infrared signals are used only for wireless networks.
Identify the organizations that developed the general cable type standards for voice and data communications that are currently in use, and identify the document name. ANSI/TVA, document C568 TWA/ANSI/EIA, document T530-A EIA/ANSI/TWA, document 802.2 TDA/EIA/TIA, document 802.11 ANSI/TIA/EIA, document T568b
E. The three organizations that collectively developed the T568b document, which defines the standard for a structured cabling system for voice and data communications, are the American National Standards Institute (ANSI), the Telecommunications Industry Association (TIA), and the Electronic Industries Alliance (EIA). All of the other options are not standards organizations or cabling standards.
Which of the following cable types and connectors are used to attach a television set to a cable television (CATV) network?
A fiber-optic cable and a straight tip (ST) connector
A coaxial cable and a Bayonet-Neill-Concelman (BNC) connector
A twisted pair cable and an RJ-45 connector
A coaxial cable and an F-type connector
An AUI cable and a vampire tap connector
D. The cable type and connector used to attach a television set to a CATV network is a coaxial cable with a screw-on F-type connector. Although CATV networks typically use fiber-optic cables and ST connectors for outdoor connections, they do not use fiber for internal connections to television sets. Coaxial cables with BNC connectors are most commonly used for Thin Ethernet LANs, not CATV network connections. Twisted pair cables and RJ45 connectors are used for Ethernet LANs and telephone networks, but not CATV networks. AUI cables and vampire tap connectors are used for Thick Ethernet networks.
Which of the following cable types is used for Thick Ethernet network segments? RG-8 RG-58 RJ-45 RJ-11
A. The cable type used for Thick Ethernet segments is a coaxial cable called RG-8. RG-58 is used exclusively on Thin Ethernet segments. RJ45 is a connector type used in twisted pair cabling for data networks. RJ11 is a connector type used in twisted pair cabling for telecommunications networks.
Which of the following cable types is used for Thin Ethernet network segments? RG-8 RG-58 RJ-45 RJ-11
B. RG-58 coaxial cable is used exclusively for Thin Ethernet segments. RG-8 cable is used for Thick Ethernet segments. RJ45 is a connector type used in twisted pair cabling for data networks. RJ11 is a connector type used in twisted pair cabling for telecommunications networks.
Which of the following telecommunications components is all but obsolete and is found only in old, analog telephone installations? 66 block 110 block Patch panel Fiber distribution panel
A. A 66 block is a type of punchdown block for telephone systems that was first introduced in 1962. By the year 2000, nearly all commercial telephone installations had begun using 110 blocks instead; 110 blocks are still in use, as are patch panels and fiber distribution panels, both of which are termination points for network cable runs.
Which of the following coaxial cable types are still in general use? (Choose all correct answers.) RG-6 RG-8 RG-58 RG-59
A and D. RG-6 and RG-59 are 75 ohm cables that are still used for cable television and similar connections. RG-8 and RG-58 are 50 ohm cables that were formerly used for Thick Ethernet and Thin Ethernet, respectively, but are no longer in general use.
Under which of the following conditions might the local building code require that a data network use plenum cable?
When multiple cables run through the same conduit
When cables run near to devices that generate electromagnetic interference (EMI)
When cables must run through heating ducts
When cable runs exceed the maximum length specified by the physical layer specification
C. A plenum space is an area of a building that provides air circulation as part of its heating or cooling system, such as a heating or air conditioning duct. Plenum cables have a sheath made of a fire retardant material that does not outgas toxic fumes should it be exposed to fire. When network cables are installed in plenum spaces, many local building codes require that installers use plenum-rated cables conforming to specific standards. Plenum cables provide no benefit when installed near other cables, or EMI sources, or when they exceed specified lengths.
Which of the following statements about the differences between fiber-optic angle-polished connectors (APCs) and ultra-polished connectors (UPCs) are true? (Choose all correct answers.)
APCs should only be joined to other APCs.
APCs generate more insertion loss that UPCs.
UPCs generate more return loss than APCs.
UPCs use a green connector boot or body.
A, B, and C. Joining an APC to a UPC creates a mismatched connection that generates an extremely high rate of insertion loss (attenuation). APCs do generate more insertion loss than UPCs and less return loss (reflection). It is APCs, not UPCs, that use green boots or bodies on the connectors.
Which of the following is not a type of fiber-optic connector? SC MTRJ ST BNC
D. Bayonet-Neill-Concelman (BNC) is a type of connector used with coaxial cable. Subscriber connector (SC), mechanical transfer registered jack (MTRJ), and straight tip (ST) are all types of fiber-optic connectors.
Which of the following physical layer transceiver module standards is the oldest and therefore the most obsolete? SFP BiDi QSFP GBIC
D. The Gigabit Interface Converter (GBIC) transceiver standard was first published in 1995 and defines a maximum data transfer rate of 1.25 Gbps. It was rendered all but obsolete by the Small Form-factor Pluggable (SFP) standard, introduced in 2001, which ran at the same maximum speed but was smaller in size. Subsequent variations on the standard, such as Quad Small Form-Factor Pluggable (QSFP), defined devices with faster transfer rates. Bidirectional (BiDi) transceivers were developed to eliminate the need for separate transmit and receive fibers by using multiplexing.
Which of the following cable types is typically configured in a star topology, uses eight copper conductors arranged in four pairs, and uses RJ-45 connectors? RG-8 Twisted pair RG-58 Fiber optic
B. There are two main types of twisted pair wiring used for data communications: unshielded twisted pair (UTP) and shielded twisted pair (STP). Both types can be used in a star topology. UTP and STP cables contain eight copper conductors twisted in four pairs. UTP and STP cables use RJ45 connectors to connect end systems to switches, patch panels, and wall plates. RG-8 and RG-58 coaxial cable can only be used in a bus topology. Fiber-optic cable can be used in a star topology, but it uses either glass or plastic conductors and doesn’t use RJ45 connectors.
Which of the following statements explains the purpose of the twists in twisted pair cabling?
The twists prevent collisions.
The twists completely eliminate crosstalk and electromagnetic interference (EMI) in adjacent wire pairs.
The twists prevent crosstalk in adjacent wire pairs and limit the effects of EMI on the signals carried over the cable.
The twists extend the bend radius allowance of the cable.
C. The twists in a twisted pair cable prevent the signals on the different wires from interfering with each other (which is called crosstalk) and also provide resistance to outside electromagnetic interference. The twists have no effect on collisions. The twists can’t completely eliminate the effects of EMI. Twists have nothing to do with the bend radius allowance for the cable.
Which of the following tools do cable installers use to add connectors such as RJ-45 and RJ-11 to twisted pair cabling? A crimper A splicer A pigtail A patch
A. A crimper or crimping tool is a jawed device that has a set of dies in it. Installers use a crimper to squeeze the two halves of an RJ45 or RJ11 connector together, with the wires inside securing the connector to the cable. Installers use a splicing tool to splice two cable segments together. There is no tool called a pigtail or a patch.
Which of the following combinations of attributes describes the cable used for a Thin Ethernet network?
RJ-45, 50-ohm, 0.270-inch, coaxial cable with BNC connectors
RG-59, 75-ohm, 0.242-inch, coaxial cable with F connectors
RG-58, 50-ohm, 0.195-inch, coaxial cable with BNC connectors
RG-8, 50-ohm, 0.405-inch, coaxial cable with N connectors
RJ-6, 75-ohm, 0.242-inch, coaxial cable with BNC connectors
C. Thin Ethernet networks use a type of 50-ohm coaxial cable called RG-58, which is 0.195 inches in diameter and uses BNC connectors. 75-ohm coaxial cable with F connectors is used for cable television networks, and RG-8 coaxial is the cable that Thick Ethernet networks use.
Which of the following connector types are typically associated with Ethernet networks? (Choose all correct answers.) F-type BNC RJ-45 DB-9 N-type
B, C, and E. Thin Ethernet networks use BNC connectors. Thick Ethernet networks use N-type connectors. All unshielded twisted pair (UTP) Ethernet networks use RJ45 connectors. F-type connectors are used with coaxial cable, typically for cable television installations. DB-9 connectors are commonly used for serial communications ports.
Which of the following connector types was typically associated with a T-connector attached to the computer? RJ45 MTRJ 8P8C BNC F-type
D. Thin Ethernet networks use a type of coaxial cable that runs from each computer to the next one, forming a bus topology. To connect the cable to the network computers, each network interface adapter has a T-connector attached to it, with two additional male BNC connectors, to which you connect two lengths of network cabling.
Which of the following connector types are associated with fiber-optic cables? (Choose all correct answers.) RJ11 ST F-type LC MTRJ
B, D, and E. Fiber-optic cable connectors all function on the same basic principles, but there are a variety of form factors from which to choose, including straight tip (ST), local connector (LC), and mechanical transfer–registered jack (MTRJ). RJ11 is a twisted pair cable connector, and F connectors are for coaxial cable.
Which of the following types of cable, when installed, sometimes employed a device called a vampire tap? Unshielded twisted pair Shielded twisted pair Multimode fiber optic Single-mode fiber optic Coaxial
E. Thick Ethernet installations used a type of coaxial cable called RG-8. To connect a node to the network, installers ran a separate cable called an attachment unit interface (AUI) cable from the computer to the RG-8 and connected it using a device called a vampire tap that pierced the sheathing to make contact with the conductors within. All of the other cable types listed use different types of connectors.
In an internal UTP cable installation, each horizontal cable run connects a wall plate in the work area to a centralized cabling nexus in a telecommunications room. Which of the following is the correct term for this cabling nexus? Telepole Demarc Backbone Patch panel
D. The cabling nexus in a telecommunications room is called a patch panel. A telepole is a tool used for installing cables. A backbone is a network that connects other local area networks (LANs) together. A demarcation point, or demarc, is the location at which a telecommunication provider’s service meets the customer’s private network.
Which of the following statements about single-mode and multimode fiber-optic cables are true? (Choose all correct answers.)
Single-mode cables can span longer distances than multimode cables.
Single-mode cables are more resistant to electromagnetic interference than multimode cables.
Single-mode cables are more difficult to install than multimode cables.
Single-mode cables have a much larger core diameter than multimode cables.
A and C. Single-mode cables are capable of spanning longer distances than multimode because they have a narrower core diameter, reducing signal dispersion rates. Because the core consists of fewer (typically one or two) strands, single-mode cables are less flexible than multimode and cannot bend around corners as easily, making them more difficult to install. Because they use light impulses rather than electricity, all fiber-optic cables are completely immune to electromagnetic interference.
Which of the following components are typically used only for telephone cable installations, and not for data networking? (Choose all correct answers.) 66 blocks 110 blocks 25 pair UTP cables 100 pair UTP cables
A, C, and D. Voice telephone networks do not have performance requirements as strict as those of data networks, so they are less liable to suffer from crosstalk and other types of interference. As a result, installers often use larger UTP cables for telephone connections. UTP cables are available in configurations containing 25 wire pairs and 100 wire pairs in a single sheath, which enables installers to service multiple users with a single cable. The punchdown blocks for UTP data networks with 8P8C connectors are called 110 blocks. The older standard for punchdown blocks is the 66 block. Rarely used for data networking, 66 blocks are still found in many telephone service installations.
Which of the following statements about single-mode fiber-optic cable are true? (Choose all correct answers.)
Single-mode cables use an LED light source, whereas multimode cables use a laser.
Single-mode cables can span longer distances than multimode cables.
Single-mode cables have a smaller core filament than multimode cables.
Single-mode cables have a smaller bend radius than multimode, making them easier to install.
Single-mode fiber-optic cables require a ground, whereas multimode cables do not.
B and C. Single-mode cables have a smaller core filament and can span longer distances than multimode cables. Single-mode cables also use a laser light source, have a larger bend radius, and do not require a ground.
Which of the following tools do cable installers use to connect bulk cable runs to wall plates and patch panels? A crimper A splicer A pigtail A punchdown block tool
D. Installers use a punchdown block tool to connect the ends of bulk cable runs to jacks in wall plates and patch panels. A crimper or crimping tool is a jawed device that enables installers to squeeze the two halves of an RJ45 or RJ11 connector together, securing the connector to the cable. Installers use a splicing tool to splice two cable segments together. There is no tool called a pigtail.
Ralph has been hired by a client to install cabling to connect two existing networks. The two networks are in different buildings approximately 1,000 feet apart. The cable type must support Gigabit Ethernet data rates of 1,000 megabits per second (Mbps) and provide a high level of resistance to electromagnetic interference (EMI). Your client wants the most economical cabling solution that meets their needs. Which of the following cable types best meets the needs of this client?
Multimode fiber-optic cable Shielded twisted pair (STP) cable Unshielded twisted pair (UTP) cable Thin coaxial cable Single-mode fiber-optic cable
A. Multimode fiber-optic cable best meets the client’s needs. Fiber-optic cable supports the required 1000 Mbps data rate and can connect networks that are more than 1,000 feet apart. Fiber-optic cable is immune to EMI. Although both multimode and single-mode fiber would meet the corporation’s general needs, multimode is best in this scenario because it is less expensive than single-mode fiber. Twisted pair wiring (STP or UTP) meets the data rate and cost requirements but does not support connections longer than 100 meters. Thin coaxial cable does not support the data rate or distances longer than 185 meters.
Which of the following are connector types used with coaxial cables? (Choose all correct answers.) BNC F-type N-type ST RJ-11
A, B, and C. BNC connectors are used for coaxial Thin Ethernet networks, and N-type connectors with Thick Ethernet. F-type connectors are used for coaxial cable television installations. Straight tip (ST) connectors are used with fiber-optic cable, and RJ11 connectors are used for telephone installations.
Alice has been hired by a corporation to design the cabling for their network. The corporation just moved in to two different floors of an older building, a retail space on the ground floor and an office space on the 43rd floor. The building has existing Category 5 (CAT5) unshielded twisted pair (UTP) cable. Alice’s client wants two separate local area networks (LANs), one on each of the two floors, with a backbone network connecting them. They want a 1 gigabit per second (Gbps) data rate for each LAN but plan on migrating to 10 Gbps in the future. The two networks are approximately 200 meters apart. Which of the following solutions best meets the client’s needs?
Install Category 6 (CAT6) or Category 6a (CAT6a) UTP cable for the LANs. These cables run at 1 Gbps and provide a migration path to 10 Gbps. Use twisted pair cable for the backbone network.
Use the existing CAT5 cabling for the LANs since CAT5 runs at 1 Gbps. Use thick coaxial cable for the backbone network.
Install CAT6 or CAT6a UTP cable for the LANs. These cables run at 1 Gbps and provide a migration path to 10 Gbps. Use multimode fiber-optic cable for the backbone network.
Install CAT6 or CAT6a UTP cable for the LANs. These cables run at 1 Gbps and provide a migration path to 10 Gbps. Use the existing CAT5 cable for the backbone network.
C. Either CAT6 or CAT6a UTP cable will provide the currently required 1 Gbps data rate, with a migration path to 10 Gbps in the future. The backbone cabling connecting the two LANs needs to be fiber optic, since it exceeds the distance limitations of twisted pair and coaxial cable. CAT5 cable conceivably runs at 1 Gbps; however, it does not run at 10 Gbps.
A maintenance worker, while replacing a light fixture in an office building, accidentally severs a network cable in the drop ceiling. The tenants use a variety of local area network (LAN) technologies throughout the structure, but on that particular floor there are three separate LANs: a 10-node Thin Ethernet LAN using coaxial cable in a bus topology, a 25-node Gigabit Ethernet LAN using twisted pair cable in a star topology, and a 5-node Fiber Distributed Data Interface (FDDI) LAN using multimode fiber-optic cable in a double ring topology. Without knowing which of the LANs the severed cable belongs to, what is the maximum number of computers that could be directly affected by the cable break? 0 1 5 10 25 40
D. The Thin Ethernet LAN is the network most endangered by the cable break. If a bus network is severed, all of the workstations on it are affected because the cable segments are no longer terminated at one end. The Gigabit Ethernet network uses a star topology, which means that only the one computer using the severed cable could be disconnected from the network. An FDDI double ring network can survive a single cable break without any workstations being affected.
In the punchdown process for unshielded twisted pair (UTP) cable, which of the following is the last step that you perform when connecting bulk cables to jacks in wall plates and patch panels?
Cut off the excess wire that protrudes past the contacts.
Press the bare wire down between the two metal contacts that hold it in place.
Strip some of the insulating sheath off the cable end to expose the wires.
Insert the wires into the appropriate contacts in the jack.
Strip a small amount of insulation off each wire.
Separate the twisted wire pairs at the ends.
A. You use a punchdown block tool to connect the ends of bulk cable runs to jacks in wall plates and patch panels. The steps of the process are as follows:
Strip some of the insulating sheath off the cable end to expose the wires.
Separate the twisted wire pairs at the ends.
Strip a small amount of insulation off each wire.
Insert the wires into the appropriate contacts in the jack.
Press the bare wire down between the two metal contacts that hold it in place.
Cut off the excess wire that protrudes past the contacts.
You must repeat the process of punching down for both ends of your internal cable runs.
Which of the following cable connector types is not used with fiber-optic cable? Straight tip (ST) Subscriber connector (SC) Mechanical transfer–registered jack (MTRJ) F-type Fiber local connector (LC)
D. ST, SC, fiber LC, and MTRJ are all connectors used with fiber-optic cables. F-type connectors are used with coaxial cables.
Which of the following twisted pair cable types can you use to construct a 10GBase-T network with 100-meter segments? (Choose all correct answers.) CAT5 CAT5e CAT6 CAT6a CAT7
D and E. Category 6a (CAT6a) twisted pair cable is a variant on CAT6 that enables you to create 10GBase-T networks with segments up to 100 meters long. Category 7 (CAT7) cable adds shielding both to the individual wire pairs and to the entire cable, for even greater resistance to crosstalk and noise. CAT7 supports 100-meter 10GBase-T segments as well. CAT5 and CAT5e are not suitable for use with 10GBase-T. You can use CAT6 for 10GBase-T, but it is limited to 55-meter segments.
Which of the following cable connector types have been rendered nearly obsolete by Universal Serial Bus (USB) connections? (Choose all correct answers.) BNC RJ-11 DB-9 DB-25
C and D. The DB-9 and DB-25 connectors were at one time ubiquitous on personal computers, providing peripheral connections to modems, printers, and other devices. They have since been largely eliminated in favor of USB. BNC connectors were used for Thin Ethernet networking, but they have been replaced by unshielded twisted pair (UTP) cable with RJ45 connectors. RJ11 connectors are used for telephone connections.
Which of the following twisted pair cable types is rated for both a 10-megabit-per-second (Mbps) data rate (using two pairs) and a 100-Mbps data rate (using four pairs)? Category 3 (CAT3) Category 5 (CAT5) Category 5e (CAT5e) Category 6 (CAT6)
A. CAT3 cable was originally intended for use in voice-grade telephone networks but was later certified for use in data networks. CAT3 cable can support data transfer rates from 4 Mbps up to 100 Mbps (using the now-deprecated 100Base-T4 and 100VG-AnyLAN standards). Although this type of cable could run at 100 Mbps, it was seldom used at speeds greater than 10 Mbps. CAT5 cable was the primary replacement for CAT3, supporting data rates up to 100 Mbps. CAT5e and CAT6 are rated for data rates up to 1 Gbps, as on Gigabit Ethernet networks. CAT6 can even support 10 Gbps transfer rates over shorter distances.
Ed has been hired to install network cabling for a small private company with 15 employees who need to share files and printers. All of the employees are physically located within the same building in two separate office spaces directly adjacent to each other, sharing a common wall and door for access. Both offices have drop ceilings. The client wants a simple Gigabit Ethernet installation that’s easy to troubleshoot. In addition, Ed’s client wants to keep installation costs to a minimum. Which of the following combinations of topology, cable type, and installation method would best meet the needs of Ed’s client?
Star topology, fiber-optic cabling, and internal installation
Bus topology, coaxial cabling, and external installation
Bus topology, twisted pair cabling, and internal installation
Star topology, coaxial cabling, and external installation
Star topology, twisted pair cabling, and external installation
E. Because the company has few employees, they are in a single location, and the client is concerned with minimizing the cost, the best solution is to use a star topology with prefabricated twisted pair cabling and an external installation method. The star topology uses a central switch. Ed can use two switches, one in each room, to connect computers to the network. Prefabricated twisted pair cabling, which has the connectors already attached and is available in specific lengths, will keep the cost to a minimum. Since the employees are all located in the same building, with a common wall and door and a drop ceiling, the external installation method is the best choice. It is not possible to use a bus topology or coaxial cable for Gigabit Ethernet. Ed could conceivably use fiber-optic cable in a star topology for Gigabit Ethernet, but it is more difficult to install and very expensive. An internal installation, which uses a combination of bulk cable with no connectors and prefabricated cables, is more expensive than an external installation and is typically used for larger networks.
Which of the following cable types are typically used in newly constructed local area network (LAN) installations? (Choose all correct answers.) Single-mode fiber optic Multimode fiber optic Coaxial Unshielded twisted pair
B and D. The main cable types used in LANs today are multimode fiber optic and unshielded twisted pair. Single-mode fiber optic is used primarily for long-distance wide area network (WAN) connections, and coaxial cable is no longer used for LANs.
Which of the following statements are true about coaxial cable? (Choose all correct answers.)
Coaxial cable has three conductors within the same sheath.
Coaxial cable has two conductors within the same sheath.
Coaxial cable has a copper core that carries light pulse signals.
Coaxial cable has a copper core that carries electrical signals.
Coaxial cable has an insulating outer sheath made of braided strands.
Coaxial cable has an insulating sheath made of either PVC or Teflon.
B, D, and F. Coaxial cable has two conductors within the same sheath that share a common axis. These conductors are surrounded by an outer insulating sheath of either PVC or Teflon. Copper cables carry electrical signals. Only fiber-optic cables carry light pulse signals.
Which of the following twisted pair cable types are rated for 1,000 megabit per second (Mbps) Gigabit Ethernet using two wire pairs? (Choose all correct answers.) Category 3 (CAT3) Category 5 (CAT5) Category 5e (CAT5e) Category 6 (CAT6) Category 6a (CAT6a) None of the above
F. All twisted pair Gigabit Ethernet implementations require all four wire pairs to achieve 1000 Mbps transfer rates.
Which of the following twisted pair cable types support both 10 megabit per second (Mbps) and 100 Mbps data rates, using only two pairs? (Choose all correct answers.) Category 3 (CAT3) Category 5 (CAT5) Category 5e (CAT5e) Category 6 (CAT6)
B, C, and D. CAT5 cable was the original cable standard intended for transfer rates up to 100 Mbps. CAT5e and CAT6 support 100 Mbps and are also rated for data rates up to 1000 Mbps. All three of these standards also support the 10 Mbps transfer rate. CAT3 can support both 10 and 100 Mbps, but it requires four pairs for 100 Mbps.
Which of the following statements about fiber-optic cabling are true? (Choose all correct answers.)
There are two fiber-optic cable types: single-mode and multimode.
Fiber-optic cable is typically used to span long distances.
Fiber-optic cables use IBM data connector (IDC) connectors.
Fiber-optic cables use straight tip (ST) and subscriber connector (SC) connectors.
Single-mode fiber-optic cable uses a laser light source and a glass core.
Multimode fiber-optic cable uses a light-emitting diode (LED) light source.
A, B, D, E, and F. Fiber-optic cable comes in two types: multimode and single-mode. Fiber-optic cables vary in light source (LED or laser), cable grade (glass or plastic), and size of the core conductor. Single-mode uses a higher-grade glass conductor with a laser light source. Multimode fiber uses an LED light source. Both types can use either ST or SC connectors to physically connect end devices to a fiber-optic network. Fiber-optic cable is used to extend networks over long distances. Fiber-optic cables do not use IDC connectors, which are intended for use with shielded twisted pair (STP) cable.
Which of the following are characteristics of an internal cable installation? (Choose all correct answers.)
An internal cable installation uses bulk spools of cabling with no connectors attached for most cable runs.
An internal cable installation uses only prefabricated cables with connectors attached for all cable runs.
An internal cable installation uses solid wire conductors for all cable runs, regardless of distance.
An internal cable installation uses stranded wire conductors for short cable runs and solid core for longer cable runs.
In an internal cable installation, cables are typically not run through walls or ceilings.
In an internal cable installation, cables are typically run through walls or ceilings.
A, D, and F. The use of bulk cable with no connectors, wall plates, and rack-mounted patch panels are all characteristics of an internal wiring installation. Internal installations typically cover large geographic areas that require cabling through walls, ceilings, and around other obstacles, making the cabling difficult to move. Solid core wiring is used for longer cable runs, whereas shorter cable runs such as connections from node to wall plate use prefabricated stranded core cables with connectors attached.
Ralph has been hired to connect three local area networks (LANs) together with redundant paths that form a fault-tolerant backbone. The LANs reside on different floors in the same building and are approximately 600 meters apart. Each LAN is currently configured in a star topology using twisted pair cabling. Each LAN includes wall plates and rack-mounted patch panels and switches. Building and fire codes allow cables to run through existing risers, ceilings, and walls, but a 50,000-watt radio station occupies one of the floors between the LANs. Which topology, cable type, and installation method is best suited for this network?
Star topology, fiber-optic cabling, and internal installation
Star topology, coaxial cabling, and external installation
Mesh topology, fiber-optic cabling, and external installation
Bus topology, twisted pair cabling, and internal installation
Mesh topology, fiber-optic cabling, and internal installation
Star topology, twisted pair cabling, and external installation
E. Ralph should use a mesh topology with redundant fiber-optic cable runs and an internal installation method. This will meet the requirements for connecting the LANs and for providing redundancy and fault tolerance. Fiber-optic cable is immune to electromagnetic interference (EMI) and can span long distances. The internal installation method is most often used in larger networks, where end systems are geographically distant, such as different buildings and floors. The star topology will not fulfill the requirements of this backbone network since it provides no redundancy. Twisted pair cable can’t span distances more than 100 meters, and it is highly susceptible to EMI. Coaxial cable can’t span distances more than 500 meters, and it is also susceptible to EMI. The bus topology cannot use twisted pair cabling and doesn’t support cable runs longer than 500 meters.
Alice is a network consultant who has been contracted to evaluate a network design created many years ago by another consultant. The client wants to know if the design is still viable. The network is to be installed in a large factory that needs 20 workstations, scattered throughout the building, to run an inventory database application. The two most distant computers are 150 meters apart. The primary goal for the network design is to connect all 20 workstations to a single local area network (LAN) running at 10 megabits per second (Mbps). The two secondary goals are to provide sufficient fault tolerance for a single cable break to occur without affecting the entire network and to provide resistance to the electromagnetic interference (EMI) generated by machinery in the factory. The design created by the other consultant calls for a Thin Ethernet LAN with all of the computers connected to a single coaxial cable segment. Which of the following statements about the proposal is true?
The solution achieves neither the primary goal nor either of the secondary goals.
The solution achieves the primary goal but neither of the secondary goals.
The solution achieves the primary goal and one of the secondary goals.
The solution achieves the primary goal and both of the secondary goals.
B. Although the design calls for an archaic technology, a Thin Ethernet network runs at 10 Mbps and can support 20 workstations over a maximum distance of 185 meters, thus achieving the primary goal. However, Thin Ethernet uses copper-based coaxial cable, which is susceptible to EMI, and it uses a bus topology, which is not tolerant of a cable break. Therefore, the solution doesn’t achieve either of the secondary goals.
Ed is a network consultant who has been contracted to design the network for a new manufacturing plant. The plant consists of two buildings 150 meters apart: an office containing 20 computers and a manufacturing facility, which has 30 computers scattered throughout it. The two most distant computers at the site are 225 meters apart. Ed’s design calls for a Gigabit Ethernet network using fiber-optic cable. On receiving the proposal, the client requests that Ed justify the additional labor and expense of installing fiber-optic cable instead of unshielded twisted pair (UTP). Which of the following is not a valid reason for choosing fiber optic over UTP for this project?
The 225 meter distance between the two most distant computers exceeds Ethernet’s maximum cable segment length for UTP.
Only fiber-optic cable can keep the two buildings electrically isolated.
Fiber-optic cable is completely resistant to any electromagnetic interference generated by the equipment in the manufacturing plant.
Fiber-optic cable provides a greater degree of tolerance to cable breaks than UTP.
D. Fiber-optic cable, in a Gigabit Ethernet installation, is not more tolerant of cable breaks than UTP. Some fiber-optic networks include fault tolerance, but Ethernet does not. Each UTP cable connecting a computer to a switch can be no longer than 100 meters, making 200 meters the maximum distance between two computers on a UTP network. Connecting two buildings with a copper-based cable creates an electrical connection between them, which can be hazardous. Fiber-optic cable does not create an electrical connection. Fiber-optic cable is also unaffected by the EMI generated by manufacturing equipment.
In the 100Base-T specification, which of the following are the functions of the fast link pulse (FLP) signals exchanged by switches and network interface adapters?
(Choose all correct answers.)
The FLP signals verify the integrity of the connection (or link) between the devices.
The FLP signals enable the devices to negotiate the speed of the link between them.
The FLP signals indicate when a collision has occurred.
The devices use FLP signals to detect bad frames.
A. FLP signals are an enhancement of the normal link pulse (NLP) signals defined in the 10Base-T standard, which verify the integrity of the link. In 100Base-T, the FLP signals retain that function, but they also enable multispeed devices to negotiate the speed at which they will operate. FLP signals do not indicate collisions or bad frames.
Which of the following 10 Gigabit Ethernet specifications calls for the use of copper cable? 10GBase-LR 10GBase-CX4 10GBase-ER 10GBase-LX4 10GBase-SR
B. The 10GBase-CX4 specification calls for the use of a twinaxial copper cable with segments no longer than 20 meters. The 10GBase-LR, 10GBase-ER, 10GBase-LX4, and 10GBase-SR specifications all call for fiber-optic cable.
Alice is a network consultant who has been contracted to upgrade an existing Ethernet network to Gigabit Ethernet. The network consists of 20 workstations with integrated 10Base-T/100Base-TX/1000Base-T network interface adapters. The network cabling is Category 5 (CAT5) unshielded twisted pair (UTP), installed when the building was constructed. All of the workstations are connected to a single 100Base-T switch. Which of the following options would Alice find to be a valid upgrade path to Gigabit Ethernet?
Replace the CAT5 cable with Category 5e (CAT5e) or Category 6 (CAT6) and leave the existing network interface adapters and switch in place.
Install a 1000Base-T network interface card in each computer and leave the existing cables and switch in place.
Replace the CAT5 cable with CAT5e or CAT6 and replace the 100Base-T switch with a 1000Base-T switch.
Replace the 100Base-T switch with a 1000Base-T switch and leave the existing cables and network interface adapters in place.
D. The multispeed network interface adapters in the computers can run at 1 Gbps speed using the existing CAT5 cable, but the 100Base-T switch must be replaced with a 1000Base-T switch. While the network might run better with a cable upgrade, it is not immediately necessary. Replacing the network interface adapters is not necessary because the existing multispeed adapters can run at 1 Gbps if they are connected to a 1000Base-T switch.
Ralph is a network consultant with a client who wants him to design the local area network (LAN) for his company’s new branch office. The site consists of a building with unshielded twisted pair (UTP) cable already installed, which the client considered a major selling point when selecting the property. He wants Ralph to install the fastest possible LAN using the existing cable. After examining the site, Ralph notes that the cable is Category 5 (CAT5), installed using a star topology, and that the individual cable runs are all less than 100 meters long. Which of the following Ethernet physical layer specifications can Ralph use for the new network to provide the fastest transmission speeds without replacing the cable? 10GBase-T 100Base-TX 1000Base-T 1000Base-LX
C. 1000Base-T is fastest Ethernet specification that can run on CAT5 UTP cable. 10GBase-T requires Category 5e (CAT5e) or Category 6 (CAT6) UTP cable. 100Base-TX can use CAT5 cable, but it runs at one-tenth the speed of 1000Base-T. 1000Base-LX is a fiber-optic specification that cannot run on CAT5 UTP or any copper cable.
Which Institute of Electrical and Electronics Engineers (IEEE) standards for Ethernet support 10 megabit per second (Mbps) communications, and what are the correct segment limitations for each standard? (Choose all correct answers.) 10Base2; segment maximum is 100 meters 10Base2; segment maximum is 185 meters 10Base5; segment maximum is 500 meters 100Base5; segment maximum is 500 meters 10Base-T; segment maximum is 100 meters 10Base-T; segment maximum is 328 meters
B, C, and E. The three IEEE 10 Mbps standards for Ethernet are 10Base2, 10Base5, and 10Base-T. 10Base2 is limited to 185-meter segments; 10Base5 is limited to 500-meter segments; and 10Base-T is limited to 100-meter segments. The other options are not valid.
Which of the following are Ethernet cable types that must be configured in a bus topology? (Choose all correct answers.) RG-8 RG-10 RG-14 RG-58
A and D. The first version of DIX Ethernet (Version 1) supported RG-8 Thick coaxial cable in a bus topology. Version 2 added support for Thin coaxial cable (RG-58) but was still limited to a bus topology. RG-10 and RG-14 are not Ethernet cable types.
Ed has been hired by a company to upgrade its network infrastructure. The current network is 10 Mbps Ethernet running on Category 5 (CAT5) twisted pair cable. There are 100 computers on the network, all of which have 10/100/1000 multispeed network interface adapters. The computers are all connected to hubs. Users are complaining that the network is too slow and connections are sometimes dropped. Management wants to upgrade to the fastest Ethernet standard possible, using the existing cabling, and still keep costs to a minimum. Which of the following implementations should Ed recommend to the client?
Upgrade to 100Base-TX and keep the existing hubs.
Upgrade to 1000Base-T and keep the existing hubs.
Upgrade to 100Base-FX and replace all of the hubs with switches.
Upgrade to 1000Base-T and replace all of the hubs with switches.
D. The best solution in this scenario is to upgrade to 1000Base-T and replace the existing hubs with switches. 1000Base-T provides the fastest transfer speeds supported by the existing cable. Since users are complaining that the network is slow with the existing hubs, it makes sense to replace the shared hub environment with switches that offer dedicated bandwidth out each port. Any solution that does not replace the hubs would not address the users’ complaints. 100Base-TX would provide a speed increase, but it runs at one-tenth the speed of 1000Base-TX. Upgrading to 100Base-FX would require the cabling to be replaced with fiber optic, which would be very expensive.
Ralph has been hired by a company to redesign its local area network (LAN). Right now it has a single 100 Mbps Ethernet LAN with 40 users and 2 shared servers, all connected through 3 hubs. The users on the network must share files with one another and also access the shared servers to retrieve and store files. The users are complaining that the network is too slow. Management states that cost is a factor that must be considered. Which of the following upgrade scenarios should Ralph recommend in this situation?
Split the network into smaller segments with dedicated hubs as opposed to shared hubs.
Split the network into two routed LANs with 20 users each.
Replace the hubs with switches to define separate collision domains and filter unnecessary traffic from each segment.
Replace the hubs with a layer 3 switch and define two virtual LANs (VLANs) with 20 users each.
C. In this situation, the best choice is to replace the hubs with switches, since the network is relatively small and cost is an issue. In addition, all users must be able to share information directly with one another and to access the servers. On the existing network, all users share the same 100 Mbps communication channel, and each computer must take turns transmitting. By replacing the hubs with switches, you provide each computer with a dedicated 100 Mbps connection to the switch, while reducing unnecessary traffic and collisions on the network. There is no such thing as a dedicated hub. Splitting the network into two routed LANs with 20 users each is not the best solution, since all users must share information on a constant basis. Also, cost is a factor and routers are more expensive than switches. Replacing the hubs with a layer 3 switch and defining two VLANs with 20 users each is not a reasonable solution because layer 3 switches are very expensive. Layer 3 switches and VLANs are typically used in larger enterprise networks.
Which of the following devices can split a single network into two collision domains while maintaining a single broadcast domain? Hub Bridge Switch Router
B. A bridge can split a single network into two collision domains, because it forwards only the packets that are destined for the other side of the bridge. The bridge forwards all broadcast packets, so it maintains a single broadcast domain. A hub maintains a single collision domain and a single broadcast domain. A switch creates a separate collision domain for each port, and a single broadcast domain for the entire network. A router creates two collision domains, but it does not forward broadcasts, so there are two broadcast domains as well.
Alice has a network that consists of three virtual LANs (VLANs) defined on all of the network’s switches. VLAN 10 is the Sales VLAN, VLAN 20 is the Marketing VLAN, and VLAN 30 is the Accounting VLAN. Users are reporting that they can’t communicate with anyone outside of their own VLAN. What is the problem, and what must Alice do?
The problem is a faulty VLAN configuration on one of the switches. Alice needs to re-create the VLANs and configure each VLAN for routing.
One of the VLANs is configured to filter all other VLAN traffic for security purposes. Alice needs to change the filter on this VLAN.
VLANs are limited to data link layer communication only. To allow communication between VLANs, Alice must add a router or a layer 3 switch to the network and configure it to route traffic between the VLANs.
The VLANs are using different data link layer protocols. VLANs must use the same data link layer protocol in order to communicate.
C. VLANs are data link layer local area networks (LANs) defined within switches. Only devices (and users) connected to ports belonging to the same VLAN can communicate with each other until a layer 3 device, such as a router or a layer 3 switch, is added to the network. Re-creating and reconfiguring the VLANs will not correct this problem. Traffic filters are usually implemented on routers. VLANs do not have to use the same data link protocol.
Which of the following functions is the multifunction device on a home or small office network known as a broadband router least likely to provide? Wireless access point Switch Proxy server DHCP server
C. Broadband routers generally do not function as proxy servers, which are application layer devices used to regulate access to the Internet. Many broadband routers are also wireless access points, enabling users to construct a LAN without a complicated and expensive cable installation. Many broadband routers have switched ports for connections to wired devices, such as printers and computers. Most broadband routers use DHCP to assign IP addresses to devices on the private network.
Which of the following is the true definition of the term modem?
A device that connects a computer to the Public Switched Telephone Network (PSTN)
A device that connects a local area network (LAN) to the Internet
A device that converts analog signals to digital signals and back again
A device that connects a local area network (LAN) to a wide area network (WAN)
C. A modulator/demodulator is any device that converts analog signals to digital signals and digital signals back to analog signals. The digital device does not have to be a computer, and the analog device does not have to be the PSTN. There are many devices that are incorrectly referred to as modems, such as devices that connect a digital LAN to a digital WAN or all-digital devices that connect computers to the Internet.
Which of the following devices is used to physically connect computers in the same VLAN? A bridge A hub A switch A router
C. Replacing routers with switches turns an internetwork into a single large subnet, and VLANs exist as logical elements on top of the switching fabric. Although VLANs are the functional equivalent of network layer subnets, the systems in a single VLAN are still connected by switches, not routers. Bridges connect network segments at the data link layer and selectively forward traffic between the segments. However, bridges do not provide a dedicated connection between two systems like a switch does, and they do not make it possible to convert a large routed internetwork into a single switched network. Therefore, they have no role in implementing VLANs. Hubs are physical layer devices that propagate all incoming traffic out through all of their ports. Replacing the routers on an internetwork with hubs would create a single shared network with huge amounts of traffic and collisions. Hubs, therefore, do not connect the computers in a VLAN.
Which of the following best describes the function of a firewall?
A device located between two networks that enables administrators to restrict incoming and outgoing traffic
A device that connects two networks together, forwarding traffic between them as needed
A device that enables Internet network clients with private IP addresses to access the Internet
A devices that caches Internet data for subsequent use by internal network clients
A. A firewall is a filter that can prevent dangerous traffic originating on one network from passing through to another network. A device that connects two networks together and forwards traffic between them is a router, not a firewall. A device that enables Internet network clients with private IP addresses to access the Internet is a description of a NAT router or a proxy server, not a firewall. A device that caches Internet data is a proxy server or caching engine, not a firewall.
Which of the following terms is used to describe the method by which a firewall examines the port numbers in transport layer protocol headers? IP address filtering Service-dependent filtering Deep packet inspection Next generation firewall
B. Service-dependent filtering blocks traffic based on the port numbers specified in the transport layer header fields. Because port numbers represent specific applications, you can use them to prevent traffic generated by these applications from reaching a network. IP address filtering operates at the network layer. Deep packet inspection (DPI) scans the contents of packets, rather than their headers. Next generation firewall (NGFW) defines a device with advanced protection capabilities; port number scanning is a basic firewall function.
Which of the following devices can also be described as a multiport repeater? Hub Bridge Switch Router
A. A repeater is a physical layer device that regenerates incoming signals and retransmits them. A hub is a type of repeater that receives data through any one of its multiple ports and retransmits the data out through all of its other ports. Bridges and switches are data link layer devices, and routers are network layer devices. None of these three can be described as multiport repeaters.
Which of the following bridging types has never been used on Ethernet local area networks (LANs)? Store and forward Transparent Source route Multiport
C. Source route bridging was a technique used on Token Ring (and not Ethernet) networks, in which a Routing Information Field (RIF) in the packet header identified the network segments the packet should follow to reach its destination. Store and forward, transparent, and multiport bridges have all been used on Ethernet networks.
Which of the following physical network devices can conceivably be implemented as software in a computer’s operating system? (Choose all correct answers.) Hub Switch Router Firewall
C and D. Most operating systems are capable of functioning as routers or firewalls. To route traffic, the system must have two network connections. A software firewall can be part of a computer’s routing functionality, or it can be a stand-alone firewall that protects only the local system. Computers cannot function as hubs or switches because multiple ports would be required and standard network adapters don’t implement those functions.
Which of the following criteria does a firewall capable of service dependent filtering use to block traffic? Hardware addresses Protocol identifiers IP addresses Port numbers
D. Service-dependent filtering blocks traffic based on the port numbers specified in the transport layer header fields. Because port numbers represent specific applications, you can use them to prevent traffic generated by these applications from reaching a network. IP address filtering enables you to limit network access to specific computers; it is not service dependent. Filtering based on hardware addresses provides the same basic functionality as IP address filtering, but it is more difficult to spoof hardware addresses than IP addresses. Filtering by protocol identifier enables you to block all traffic using TCP or UDP; it is not service dependent.
Ralph is a freelance network consultant installing a three-node small business network. The computers are all in the same room and use wired Ethernet to connect to the switched ports of a multifunction device. The device also functions as a network address translation (NAT) router for a cable modem connection to the Internet and uses DHCP to assign private IP addresses to the computers. Although NAT provides a measure of security, Ralph wants to be sure that the computers on the network are protected from unauthorized Internet traffic and attacks against open ports. Which of the following solutions would enable Ralph to accomplish this goal with the minimum cost to the client?
Install a hardware firewall between the multifunction device and the cable modem.
Install an intrusion prevention system (IPS) between the multifunction device and the cable modem.
Install a personal firewall on each of the computers.
Connect an intrusion detection system (IDS) to one of the switched ports in the multifunction device.
Use a port scanner to monitor the traffic entering the open ports on the computers.
C. A personal firewall is an inexpensive way to protect an individual computer from Internet incursions. Three copies of the product are much less expensive than any of the other suggested solutions. Installing a hardware firewall is a complex and expensive solution, not suitable for a small network. An IPS is a relatively expensive solution, suitable for larger networks. An IDS is a relatively expensive solution, and connecting it to a switched port would not enable it to protect the other computers on the network. A port scanner is a device that performs scans on demand. It does not continuously monitor ports, and it does nothing to protect them.
Which of the following statements about hubs and switches are true? (Choose all correct answers.)
Hubs operate at the physical layer, whereas switches operate at the network layer.
All of the devices connected to a hub are part of a single-collision domain, whereas each device connected to a switch has its own collision domain.
There are switches available with network layer functionality, but there are no hubs with that capability.
Switches create a separate broadcast domain for each collected device, whereas hubs create a single broadcast domain for all of the connected devices.
B and C. Hubs operate at the physical layer and switches at the data link layer. Hubs and switches both create a single broadcast domain for all of the connected devices. Switches create a separate collision domain for each connected device, whereas hubs create a single-collision domain. There are switches (but not hubs) with network layer (layer 3) functionality.
Which of the following problems is the Spanning Tree Protocol (STP) intended to prevent? (Choose all correct answers.) Broadcast storms Late collisions Bridging loops Crosstalk
A and C. STP disables redundant links between switches that can allow packets to circulate endlessly around the network. This is called a bridging loop. As a result of a bridging loop, the network can be flooded with broadcast traffic, which is called a broadcast storm. STP does nothing to prevent late collisions, which is an Ethernet timing problem, or crosstalk, which is a cabling fault.
Which two of the following devices perform essentially the same function? (Choose two correct answers.) Hubs Bridges Switches Routers
B and C. A switch is essentially a multiport bridge. Both switches and bridges process incoming packets by scanning their data link layer hardware addresses and forwarding the packets out the port connected to the destination system. The primary difference between them is that switches have many ports, whereas bridges have only two. Hubs and routers are physical layer and network layer devices, respectively, and perform different functions.
Which of the following is the term for the area between two firewalls, on which web and email servers are typically found? (Choose all correct answers.) DMZ Berlin wall Peripheral network Perimeter network
A and D. Servers that must be accessible to clients on the Internet, such as web and email servers, are typically isolated from the internal network by one firewall and from the Internet by a second firewall. The area where these servers reside is often called a perimeter network, or a demilitarized zone (DMZ). It is not called a peripheral network or a Berlin wall.
Which of the following switch types immediately forwards frames after looking at only the destination address? Cut-through Source route Store-and-forward Destination switch
A. Cut-through switches are fast because they look at only the first six bytes (the destination media access control, or MAC, address) when forwarding a frame. They do not perform a cyclical redundancy check (CRC) on the entire frame’s contents prior to forwarding it out a port leading to the destination. Source route is a bridging technique in which the source host, not the switch, determines the path a frame will take through a network to reach a destination. Store-and-forward switches take in the entire frame and verify its contents by performing a CRC calculation before forwarding it. There is no switch called a destination switch.
Which of the following statements about the Spanning Tree Protocol (STP) is not true?
STP operates at the data link layer of the OSI model.
STP is implemented in switches.
STP prevents traffic from circulating endless around a network.
STP compiles a database containing the IP addresses of connected devices.
D. STP operates at the data link layer of the OSI model, so it works with hardware addresses, not IP addresses. Switches use STP to prevent redundant links from causing traffic loops on the network.
Which of the following is the correct term for the process by which the Spanning Tree Protocol (STP) on a switch evaluates the paths through the network and places each port in the forwarding or blocking state? Assimilation Convergence Tree-building Listening
B. The process by which STP populates its database with information about each port in a switch and designates the ports as forwarding or blocking is called convergence.
Which of the following technologies would you be less likely to find on the average home or small office network? NAT DHCP 10GBase-T VLAN
C and D. Home and small office networks typically consist of a single subnet and require only a basic switch without the advanced virtual LAN capabilities that enable administrators to create separate subnets. Most home and small office networks have a DHCP server that assigns IP addresses and other TCP/IP configuration settings to clients. The DHCP server can be integrated into a broadband router or another Internet access sharing solution. Most home and small office networks support network address translation, enabling them to use private IP addresses and still access the Internet. 10GBase-T is the designation for UTP-based 10 Gigabit Ethernet, which is an advanced standard for network interface adapters often found in servers.
Which of the following is something that only a firewall capable of stateful packet inspection can do?
Scan transport layer header fields for evidence of SYN floods
Filter traffic based on port numbers
Block traffic destined for specific IP addresses
Block all TCP traffic from entering a network
A. A firewall that supports stateful packet inspection examines other network and transport layer header fields, looking for patterns that indicate damaging behaviors, such as IP spoofing, SYN floods, and teardrop attacks. Port number filtering is the most commonly used form of packet filtering; it is not the same as stateful packet inspection. Blocking traffic based on IP addresses prevents specific systems from accessing a network; stateful packet inspection is a much more complicated operation. Packet filtering based on protocol identifiers enables you to block TCP traffic; this is not stateful packet inspection.
In local area networking, which of the following is not a type of bridge? Store and forward Routing Transparent Multiport
B. Bridges are data link layer (layer 2) devices. Routing is a network layer (layer 3) function, so it is not a type of bridge. A store-and-forward, or simple, bridge examines each packet and decides whether to forward it to the connected network. A transparent bridge compiles a database of forwarding information, based on the packets it has processed previously. A multiport bridge provides connections to multiple networks; a switch is a type of multiport bridge.
VLANs create the administrative boundaries on a switched network that are otherwise provided by which of the following devices? Hubs Routers Firewalls Bridges
B. Connecting subnets with routers at the network layer maintains the data link layer administrative boundaries that prevent broadcast transmissions from being propagated throughout the entire internetwork. Switching eliminates those data link layer boundaries, and administrators can use VLANs to simulate them. Because hubs propagate all of the traffic they receive out through all of their ports indiscriminately, they create no administrative boundaries. Firewalls are filtering devices that protect networks against malicious traffic. Their functions are not related to VLANs. Switches are essentially multiport bridges that forward incoming traffic only to the device for which it is destined. Therefore, bridges are more closely related to eliminating administrative boundaries than to establishing them.
Which of the following devices can you use to connect two multimode fiber-optic Ethernet networks in different buildings 2,000 meters apart using a single-mode fiber-optic cable segment running at the same speed, while maintaining a single collision domain? Bridge Switch Router Media converter
D. A simple media converter is a physical layer device that can connect different types of network media together, as long as they have the same speed and duplex settings. Because the converter simply retransmits the signals, the single-collision domain is maintained. Bridges and switches are data link layer devices that create multiple-collision domains. Routers are network layer devices that create separate collision and broadcast domains.
At which layer of the Open Systems Interconnection (OSI) model do wireless range extenders operate? Physical Data link Network Transport Session Presentation Application
A. Wireless range extenders are physical layer devices that receive signals from wireless access points and network adapters and retransmit them, enabling devices to connect that are farther apart than the network would normally support. Because the extenders do not process the packets in any way, but just retransmit the signals, they do not operate at any layer above the physical.
Which of the following is another term for a multiport bridge? Router Switch Hub Gateway
B. A switch is a data link layer device that essentially performs the function of a bridge for each device connected to one of its ports. It can therefore be described as a multiport bridge. Routers, hubs, and gateways are devices that operate at the network, physical, and application layers, respectively, so they cannot be described as bridges.
Which of the following devices enables two computers to communicate when they are using different protocols at each layer of the Open Systems Interconnection (OSI) reference model? A router A switch A hub A gateway
D. A gateway enables two devices using different protocols to communicate by performing translation and conversion services for them. Routers, hubs, and switches all require the same protocol at some of the OSI model layers.
Review the following figure. How many collision domains and broadcast domains exist in the network diagram?
Image shows network through one router at center is connected to three different hubs wherein each hub is connected to three different systems.
There are three collision domains and three broadcast domains.
There is one collision domain and three broadcast domains.
There is one broadcast domain and three collision domains.
There are no collision domains and only one broadcast domain.
There are nine collision domains and three broadcast domains.
https://learning.oreilly.com/api/v2/epubs/urn:orm:book:9781119432128/files/images/c02g0001.jpg
A. Each port on a router defines a separate collision domain. Hubs forward all traffic to all of the connected nodes, so each network segment is a single-collision domain. Routers do not forward broadcasts, so each network segment is also a separate broadcast domain.
