Network+ Guide to Networks 6th Edition by Tamara Dean - Test Bank

Network+ Guide to Networks 6th Edition by Tamara Dean – Test Bank

 

Instant Download – Complete Test Bank With Answers

 

 

Sample Questions Are Posted Below

 

Chapter 5: Topologies and Ethernet Standards

 

TRUE/FALSE

 

1. Modern Ethernet networks are based on the star topology.

 

ANS:  T                    PTS:   1                    REF:   202

 

2. The smallest LANs do not have a backbone.

 

ANS:  F                    PTS:   1                    REF:   205

 

3. A serial backbone is the simplest kind of backbone.

 

ANS:  T                    PTS:   1                    REF:   205

 

4. The most popular method for connecting nodes on a network is circuit switching.

 

ANS:  F                    PTS:   1                    REF:   210

 

5. A network’s access method is its method of controlling how network nodes access the communications channel.

 

ANS:  T                    PTS:   1                    REF:   212

 

MULTIPLE CHOICE

 

1. A physical topology ____.

a.	specifies device types	c.	specifies connectivity methods
b.	depicts a network in broad scope	d.	specifies addressing schemes

 

 

ANS:  B                    PTS:   1                    REF:   199

 

2. Without ____, a bus network would suffer from signal bounce.

a.	hubs	c.	terminators
b.	repeaters	d.	jamming

 

 

ANS:  C                    PTS:   1                    REF:   199

 

3. In a ring network, each workstation acts as a(n) ____ for the transmission.

a.	repeater	c.	terminator
b.	amplifier	d.	manager

 

 

ANS:  A                    PTS:   1                    REF:   200

 

4. A complex combination of topologies is known as a ____ topology.

a.	mixed	c.	compound
b.	hybrid	d.	mulitpart

 

 

ANS:  B                    PTS:   1                    REF:   203

 

5. The most common logical topologies are ____ and ring.

a.	bus	c.	wired
b.	star	d.	hybrid

 

 

ANS:  A                    PTS:   1                    REF:   204

 

6. A ____ is simply a linked series of devices.

a.	star	c.	ring
b.	star-wired ring	d.	daisy-chain

 

 

ANS:  D                    PTS:   1                    REF:   205

 

7. In packet switching, when packets reach their destination node, the node ____ them based on their control information.

a.	disassembles	c.	reassembles
b.	deletes	d.	separates

 

 

ANS:  C                    PTS:   1                    REF:   210

 

8. Collectively, MPLS labels are sometimes called a ____.

a.	header	c.	frame
b.	shim	d.	title

 

 

ANS:  B                    PTS:   1                    REF:   211

 

9. All Ethernet networks, independent of their speed or frame type, use an access method called ____.

a.	CSMA	c.	CSAM/CD
b.	CSMA/DC	d.	CSMA/CD

 

 

ANS:  D                    PTS:   1                    REF:   212

 

10. A ____ occurs when two transmissions interfere with each other.

a.	jam	c.	carrier sense
b.	collision	d.	multiple access event

 

 

ANS:  B                    PTS:   1                    REF:   212

 

11. On an Ethernet network, a(n) ____ is the portion of a network in which collisions occur if two nodes transmit data at the same time.

a.	collision domain	c.	interference domain
b.	crash domain	d.	duplicate domain

 

 

ANS:  A                    PTS:   1                    REF:   212

 

12. 1000Base-T is a standard for achieving throughputs ____ times faster than Fast Ethernet over copper cable.

a.	2	c.	10
b.	5	d.	100

 

 

ANS:  C                    PTS:   1                    REF:   216

 

13. The 10GBase-T standard is considered a breakthrough for transmitting 10 Gbps over ____ medium.

a.	coaxial	c.	fiber
b.	twisted pair	d.	atmosphere

 

 

ANS:  B                    PTS:   1                    REF:   216

 

14. The most common 1-Gigabit Ethernet standard in use today is ____.

a.	1000Base-T	c.	10GBase-SR
b.	1000Base-SX	d.	1000Base-LX

 

 

ANS:  D                    PTS:   1                    REF:   217

 

15. 1000Base-SX has a maximum throughput of ____.

a.	1 Gbps	c.	100 Gbps
b.	10 Gbps	d.	1000 Gbps

 

 

ANS:  A                    PTS:   1                    REF:   217

 

16. The 10-gigabit fiber optic standard with the shortest segment length is ____.

a.	10GBase-T	c.	10GBase-LR
b.	10GBase-SR	d.	10GBase-ER

 

 

ANS:  B                    PTS:   1                    REF:   218

 

17. In the 10GBase-LR standard, the L stands for ____.

a.	long reach	c.	long ring
b.	LAN	d.	little ring

 

 

ANS:  A                    PTS:   1                    REF:   218

 

18. Given their long-distance capabilities, 10GBase-ER and 10GBase-EW are best suited for use on ____.

a.	VANs	c.	LANs
b.	MANs	d.	WANs

 

 

ANS:  D                    PTS:   1                    REF:   219

 

19. Within Ethernet frame types, the ____ signals to the receiving node that data is incoming and indicates when the data flow is about to begin.

a.	FCS	c.	preamble
b.	header	d.	frame

 

 

ANS:  C                    PTS:   1                    REF:   221

 

20. Together, the FCS and the header make up the ____-byte “frame” for the data.

a.	15	c.	21
b.	18	d.	24

 

 

ANS:  B                    PTS:   1                    REF:   221

 

21. The Ethernet II frame type contains a 2-byte ____ field that differentiates it from other Ethernet frame types.

a.	data	c.	source
b.	length	d.	type

 

 

ANS:  D                    PTS:   1                    REF:   222

 

COMPLETION

 

1. In a(n) ____________________ topology, every node on the network is connected through a central device, such as a hub, router, or switch.

 

ANS:  star

 

PTS:   1                    REF:   201

 

2. A network ____________________ is the part of a network to which segments and significant shared devices connect.

 

ANS:  backbone

 

PTS:   1                    REF:   205

 

3. ____________________ is a component of a network’s logical topology that determines how connections are created between nodes.

 

ANS:  Switching

 

PTS:   1                    REF:   209

 

4. As part of CSMA/CD, a process known as ____________________ allows the NIC issue a special 32-bit sequence that indicates to the rest of the network nodes that its previous transmission was faulty and that those data frames are invalid.

 

ANS:  jamming

 

PTS:   1                    REF:   212

 

5. Because of its support for multiple Network layer protocols and because it uses fewer bytes as overhead, ____________________ is the frame type most commonly used on contemporary Ethernet networks.

 

ANS:

Ethernet II (DIX)

Ethernet II

DIX

 

PTS:   1                    REF:   222

 

MATCHING

 

Match each item with a statement below:

a.	PSE	f.	802.3ae
b.	1000Base-LX	g.	802.3z
c.	10Base-T	h.	802.3u
d.	100Base-T	i.	PD
e.	1000Base-T

 

 

1. Follows the 5-4-3 rule of networking.

 

2. The most common 1-Gigabit Ethernet.

 

3. Also known as Gigabit Ethernet.

 

4. Refers to the PoE device that receives the power.

 

5. Also known as Fast Ethernet.

 

6. Refers to the PoE device that supplies the power.

 

7. IEEE standard for fiber-optic Ethernet networks transmitting data at 10 Gbps.

 

8. IEEE standard for fiber-optic Ethernet networks transmitting data at 1 Gbps.

 

9. IEEE standard for fiber-optic Ethernet networks transmitting data at 100 Mbps.

 

1. ANS:  C                    PTS:   1                    REF:   215

 

2. ANS:  B                    PTS:   1                    REF:   217

 

3. ANS:  E                    PTS:   1                    REF:   216

 

4. ANS:  I                     PTS:   1                    REF:   223

 

5. ANS:  D                    PTS:   1                    REF:   215

 

6. ANS:  A                    PTS:   1                    REF:   222-223

 

7. ANS:  F                    PTS:   1                    REF:   218

 

8. ANS:  G                    PTS:   1                    REF:   217

 

9. ANS:  H                    PTS:   1                    REF:   215

 

SHORT ANSWER

 

1. Describe the advantage of the star topology.

 

ANS:

Because they include a centralized connection point, star topologies can easily be moved, isolated, or interconnected with other networks; they are, therefore, scalable. For this reason, and because of their fault tolerance, the star topology has become the most popular fundamental layout used in contemporary LANs.

 

PTS:   1                    REF:   202

 

2. Explain how the star-wired bus topology works. Include a description of its drawbacks and benefits.

 

ANS:

In a star-wired bus topology, groups of workstations are star-connected to connectivity devices and then networked via a single bus, as shown in Figure 5-5. With this design, you can cover longer distances and easily interconnect or isolate different network segments. One drawback is that this option is more expensive than using the star topology alone because it requires more cabling and potentially more connectivity devices. However, compared with the benefits, these drawbacks are negligible. The star-wired bus topology forms the basis for modern Ethernet networks, which commonly use switches or routers as the connectivity devices.

 

PTS:   1                    REF:   203

 

3. Explain why it is important to understand logical topologies.

 

ANS:

Understanding logical topologies is useful when troubleshooting and designing networks. For example, on Ethernet networks, it is necessary to understand that all of a segment’s broadcast traffic is transmitted to all of the segment’s nodes. As an example, suppose you connect your laptop to your company’s Ethernet network. In an attempt to contact a DHCP server and obtain an IP address, your laptop issues a DHCP discover packet in broadcast fashion. Therefore, the packet is sent to every workstation connected to the same Ethernet segment as your laptop, even though the request wasn’t meant for them.

 

PTS:   1                    REF:   204

 

4. Explain how the distributed backbone is connected. Include a description of its benefits.

 

ANS:

A distributed backbone consists of a number of connectivity devices connected to one or more central connectivity devices, such as switches or routers, in a hierarchy. This kind of topology allows for simple expansion and limited capital outlay for growth, because more layers of devices can be added to existing layers.

 

PTS:   1                    REF:   206

 

5. Briefly explain how CSMA/CD works.

 

ANS:

In CSMA/CD, when a node wants to transmit data it must first access the transmission media and determine whether the channel is free. If the channel is not free, it waits and checks again after a very brief amount of time. If the channel is free, the node transmits its data. Any node can transmit data after it determines that the channel is free.

 

PTS:   1                    REF:   212

 

6. Explain the 5-4-3 rule of networking.

 

ANS:

10Base-T follows the 5-4-3 rule of networking. This rule says that, between two communicating nodes, the network cannot contain more than five network segments connected by four repeating devices, and no more than three of the segments may be populated (at least two must be unpopulated). The maximum distance that a 10Base-T segment can traverse is 100 meters. To go beyond that distance, Ethernet star segments must be connected by additional hubs or switches to form more complex topologies. This arrangement can connect a maximum of five sequential network segments, for an overall distance between communicating nodes of 500 meters.

 

PTS:   1                    REF:   215

 

7. Within an Ethernet frame, describe the FCS (Frame Check Sequence) field and explain how it is used to make the header.

 

ANS:

All Ethernet frames contain a 4-byte FCS (Frame Check Sequence) field. Recall that the function of the FCS field is to ensure that the data at the destination exactly matches the data issued from the source using the CRC (Cyclic Redundancy Check) algorithm. Together, the FCS and the header make up the 18-byte “frame” for the data.

 

PTS:   1                    REF:   221

 

8. Within an Ethernet frame, describe what happens if fewer than 46 bytes of data are supplied by the higher layers.

 

ANS:

If fewer than 46 bytes of data are supplied by the higher layers, the source node fills out the data portion with extra bytes until it totals 46 bytes. The extra bytes are known as padding and have no significance other than to fill out the frame. They do not affect the data being transmitted.

 

PTS:   1                    REF:   221

 

9. What does the SFD identify?

 

ANS:

The SFD (start-of-frame delimiter) identifies where the data field begins.

 

PTS:   1                    REF:   221

 

10. Briefly describe the IEEE 802.3af standard. Use an analogy and explain why it is useful.

 

ANS:

In 2003, IEEE released its 802.3af standard, which specifies a method for supplying electrical power over Ethernet connections, also known as PoE (Power over Ethernet). Although the standard is relatively new, the concept is not. In fact, your home telephone receives power from the telephone company over the lines that enter your residence. This power is necessary for dial tone and ringing. On an Ethernet network, carrying power over signaling connections can be useful for nodes that are far from traditional power receptacles or need a constant, reliable power source.

 

PTS:   1                    REF:   222