CH 5

850 nm multimode fiber is used in LANs ________. A) to keep cost low B) to have the longest transmission distances C) both A and B D) neither A nor B

A

A local area network operates ________. A) on a customer premises B) between customer premises C) both A and B D) neither A nor B

A

At what layer is the 100BASE-TX standard? A) physical B) data link C) Internet D) physical and data link

A

Ethernet addresses were formerly called ________ addresses. A) MAC B) EUI-48 C) both A and B D) neither A nor B

A

Ethernet became the dominant LAN technology because of ________. A) low cost B) high speed C) link reliability D) agility

A

Ethernet forwarding devices are ________. A) switches B) routers C) access points D) both A and B

A

Ethernet messages are ________. A) frames B) packets C) segments D) not named

A

Ethernet standards are specified at the ________ layer. A) physical B) Internet C) both A and B D) neither A nor B

A

Having only a single possible path between devices ________. A) reduces switching cost B) provides reliability C) reduces errors D) none of the above.

A

How long (in milliseconds) is a clock cycle if I transmit 400 Mbps with four states? A) 0.000005 B) 0.0025 C) 0.005 D) none of the above

A

The strength of a wave is its ________. A) amplitude B) frequency C) wavelength D) force

A

To manage their Ethernet networks, companies rely on ________. A) SNMP B) HTTP C) FTTH D) none of the above

A

To prevent anyone from simply walking up to a corporate switch and plugging their computer into its Ethernet port, companies can use ________. A) 802.1X B) SNMP C) VLANs D) 802.1AE

A

4-pair UTP terminates in a(n) ________ connector. A) USB B) RJ-45 C) SC D) standard telephone

B

A system with 16 states can transmit ________ bits per clock cycle A) 3 B) 4 C) 5 D) none of the above

B

Ethernet has reliability issues because of its ________. A) too-simple switch operation B) hierarchical organization C) both A and B D) neither A nor B

B

Fiber that has a core diameter of 8.3 microns is ________. A) multimode fiber B) single-mode fiber C) full duplex fiber D) exceptionally fast

B

For what specific purpose were the 2.5GBASE-T and 5GBASE-T standards developed? A) general growth in demand for Ethernet speed B) serving access points C) to provide lower-cost service than 10G-BASE-T D) none of the above

B

CAT 5e and CAT 6 wiring can carry Ethernet traffic 100 meters up to ________. A) 10 Mbps B) 100 Mbps C) 1 Gbps D) 10 Gbps

C

Ethernet standards are specified at the ________ layer. A) physical B) data link C) both A and B D) neither A nor B

C

In Ethernet, switches are organized in a ________. A) ring B) mesh C) hierarchy D) any of the above

C

In digital signaling, there is (are) ________ state(s). A) one B) only two C) a small number of D) an infinite number of

C

Physical layer standards govern ________. A) signaling B) physical connectors C) both A and B D) neither A nor B

C

RSTP ________. A) can increase reliability B) was created to break accidental loops C) both A and B D) neither A nor B

C

The longest transmission distances are possible with ________. A) USB B) UTP C) single-mode fiber D) multimode fiber

C

The two tag frames provide information about ________. A) transmission media B) the length of Jumbo packets C) priority D) all of the above

C

ARP cache poisoning is ________. A) a DoS attack B) a DDoS attack C) an illegal login attack D) a man-in-the middle attack

D

After an ARP cache poisoning attack, the ARP cache gives the ________. A) IP address of the router the user wishes to send to B) EUI-48 address of the router the user wishes to send to C) IP address of the router the MITM attacker D) EUI-48 address of the router the MITM attacker

D

EUI-48 addresses in expressed in hexadecimal notation if used by ________. A) switches B) routers C) both A and B D) neither A nor B

D

If you can span the distance between two switches with either a single optical fiber link or two UTP lengths with an intermediate switch, which should you choose? A) single optical fiber link B) two UTP cords with an intermediate switch C) both are equally attractive D) neither will work

A

If you double the number of states, you can transmit ________ more bit(s) per clock cycle. A) 1 B) 2 C) 4 D) none of the above

A

In large Ethernet networks, there can be ________ possible data links between two hosts. A) 1 B) 2 C) 3 D) many

A

Modal dispersion limits transmission distance in ________. A) multimode fiber B) single-mode fiber C) both A and B D) neither A nor B

A

Ethernet standards are specified at the ________ layer. A) Internet B) transport C) both A and B D) neither A nor B

D

In this book, we use the terms Ethernet and 802.3 interchangeably.

True

In 4-pair UTP, what is twisted? A) individual wires B) pairs of wires C) all eight wires D) none of the above

B

In binary signaling, there is (are) ________ state(s). A) one B) two C) between three and ten D) an infinite number of

B

What is 9 hex in binary? A) 1000 B) 1001 C) 1010 D) 1111

B

What is binary 0010 in hex? A) 1 B) 2 C) 3 D) none of the Above

B

What is the quality designator for multimode optical fiber? A) Cat B) OM C) both A and B D) neither A nor B

B

________ fiber is being sold today. A) OM2 B) OM4 C) both A and B D) neither A nor B

B

All Ethernet switches are manageable.

False

The switch knows the type of device it is forwarding a frame to. Answer: FALSE

False

If a physical link can use either 4-pair UTP, multimode fiber, or single-mode fiber, which should I use? A) 4-pair UTP B) multimode fiber C) single-mode fiber D) none of the above

A

In optical fiber, light travels through the ________. A) core B) cladding C) both A and B

A

Physical layer standards govern ________. A) signaling B) frames C) packets D) all of the above

A

The 802.11ac Wi-Fi standard uses 256 states. How many bits can it send per clock cycle? A) 8 B) 16 C) 32 D) none of the above

A

The PAD field is added by the ________ if the frame is too short without it. A) sender B) receiver C) both A and B D) neither A nor B

A

Trunk links connect switches to ________ switches. A) core B) workgroup C) both A and B D) neither A nor B

A

UTP and fiber distance limits are for ________. A) physical links B) data link C) Internet routes D) physical and data link

A

UTP categories rate the ________ of UTP cabling. A) quality B) speed C) quality-of-service performance D) error performance

A

What is binary 0000 in hex? A) 0 B) 1 C) 15 D) 16

A

What organization (most specifically) creates Ethernet standards? A) IEEE B) IETF C) ISO D) OSI

A

Which core diameter is used in multimode fiber. A) 50 microns B) 8 microns C) 50 mm D) 8 mm

A

Which light wavelength dominates in LANs? A) 850 nm B) 1,310 nm C) 1,550 nm D) 1 Gbps

A

Which of the following is used most often in LANs for fiber transmission links? A) 850 nm multimode fiber B) 850 nm single-mode fiber C) 850 nm multimode-mode fiber D) 1,550 nm single-mode fiber

A

________ links connect switches to other switches. A) Trunk B) Long C) Access D) Workgroup

A

Signal state is held constant in a clock cycle ________. A) for energy efficiency B) to make it easier for the receiver to sample the state C) to emphasize differences between clock cycles D) none of the above

B

The ARP cache gives the ________ of a router the host will send a packet to. A) IP address B) EUI-48 address C) MAC address D) host name

B

The ability to transmit in two directions simultaneously is ________. A) parallel communication B) full-duplex communication C) both A and B D) neither A nor B

B

The distance between two corresponding points in adjacent cycles is the ________. A) frequency B) wavelength C) bandwidth D) span

B

The main benefit of parallel transmission over serial transmission is ________. A) reliability B) speed C) both A and B D) neither A nor B

B

The path a message takes from the source host to the destination device in an Ethernet network is a ________. A) physical link B) data link C) route D) label-switched route

B

What type of copper wiring is widely used in Ethernet? A) optical fiber B) 4-pair UTP C) both A and B D) neither A nor B

B

What type of switch connects switches to other switches? A) trunk switches B) core switches C) workgroup switches D) none of the above

B

Which UTP quality levels are needed to send signals 100 meters at 10 gigabits per second? A) category 6 B) category 6A C) both A and B D) neither A nor B

B

________ is the official name for Ethernet addresses. A) MAC B) EUI-48 C) both A and B D) neither A nor B

B

To transmit five bits per clock cycle, you must have ________ states. A) 5 B) 16 C) 32 D) none of the above

C

To transmit three bits per clock cycle, you must have ________ states. A) 3 B) 6 C) 8 D) 16

C

Two switches that are 200 m apart at a speed of 20 Gbps should be connected using ________. A) 10GBASE-SR B) 100GBASE-SR C) 10GBASE-SR with bonding D) 100GBASE-SR with bonding

C

Using RSTP to provide backup links in Ethernet ________. A) is automatic B) is simple C) is challenging D) is impossible

C

What 802 Working Group creates Ethernet standards? A) 802.1 B) 802.2 C) 802.3 D) 802.11

C

What is F hex in binary? A) 1001 B) 1010 C) 1111 D) none of the above

C

What problem limits transmission distance in 4-pair UTP? A) reflection at the two ends B) heat conduction C) radiation D) none of the above

C

When a user attempts to plug into an Ethernet switch protected by 802.1X, ________. A) the switch will freeze B) the switch port will freeze C) the user will be required to authenticate himself or herself D) none of the above

C

Which UTP quality levels can send signals at 10 gigabits per second? A) category 6 B) category 6A C) both A and B D) neither A nor B

C

Which of the following provides security in Ethernet? A) RSTP B) SNMP C) VLANs D) all of the above

C

________ links connect users to workgroup switches. A) Trunk B) Core C) Access D) Workgroup

C

________ occurs when the light energies of two pulses arrive at the far end at overlapping times. A) Multimode transmission B) Modal bandwidth C) Modal dispersion D) Modal interference

C

Four-pair UTP uses ________ connectors. A) universal B) binary C) ST or SC D) none of the above

D

How many wires are there is a UTP Ethernet cord? A) 1 B) 2 C) 4 D) 8

D

Optical fiber cords typically have two fiber strands. This is done to allow ________. A) redundancy B) total redundancy C) half-duplex operation D) full-duplex operation

D

Optical fiber cords use two strands ________. A) for reliability through redundancy B) to form a complete electrical loop C) to double the transmission speed D) for full-duplex transmission

D

To prevent an unauthorized user from sending supervisory commands to switches, companies use ________. A) 802.1X B) SNMP C) VLANs D) 802.1AE

D

To span the distance between two switches, why is adding an intermediate switch not an attractive choice? A) latency B) errors C) speed restrictions D) expense

D

What is binary 1111 in hex? A) 10 B) 13 C) 14 D) 15

D

What type of switch connects users to the network? A) user switches B) core switches C) access switches D) workgroup switches

D

Which of the following is used most often in LANs for fiber transmission links? A) modal bandwidth fiber B) 1.550 nm fiber C) single-mode fiber D) multimode fiber

D

Which of the following letters may appear in EUI-48 addresses? A) D B) H C) both A and B D) neither A nor B

D

________ describe light entering a fiber's core at different angles. A) Co-cycle waves B) Harmonics C) Divergences D) Different modes

D

A switch knows the entire data link between the source and destination hosts.

False