Questions and Answers of Business Data Networks

a. If a sub-net part is X bits long, how many sub-nets can you have?1a.) If your sub-net part is 8 bits long, you can have ______ sub-nets.a. 64b. 128c. 256d. 254b. If you have a sub-net part of 9
a. Why can TCP handle long application messages?25a.) Which of the following can handle an application message that is one megabyte in size?a. TCPb. UDPc. Both A and Bd. Neither A nor Bb. Why can UDP
a. What is a FIN segment?25a.) A TCP _______ segment is a request to the other transport process to close a connection.a. FINb. ACKc. CLSd. SYNb. Distinguish between four-way closes and abrupt
a. How long are sequence and acknowledgment numbers?24a.) Sequence numbers are ______ bits longa. 8b. 16c. 24d. 32b. How many flag fields do TCP headers have?24b1.) One-bit fields are called ______
a. Why is handling options the way that IPv4 does undesirable?23a) Which has a better system for handling options beyond the main header?a. IPv4b. IPv6c. Both use the same method.d. Neither can
a. How do the Version Number Fields in IPv4 and IPv6 differ?22a.) The version number field in IPv6 has the value ______.a. 0001b. 0100c. 0101d. 0110b. What is the general purpose of the DiffServ
a. Write the following IPv6 address in canonical form using RFC 5952: 2001:0ed2:056b:00d3:000c:abcd:0bcd:0fe0.21a.) If I simplify the address 2001:0000:0000:00fe:0000:0000:0000:cdef, I get
a. Why are IPv6 addresses simplified?20a.) IPv6 addresses are simplified ________.a. To simplify writingb. To simplify memorizationc. Both A and Bd. Neither A nor Bb. Why must simplification rules be
a. What has been holding back the adoption of IPv6?19a.) What is pushing IPv6 adoption now?a. Pressure from ISPsb. Pressure from the IETFc. Pressure from ISOd. None of the above
a. What is the main problem with IPv4 that IPv6 was created to solve?18a1.) The version of Internet Protocol that is growing rapidly is IP version _______.a. 1b. 2c. 4d. None of the above18a2.) Which
What problem is caused by the way that IPv4 handles options?
a. What does a router do if it receives a packet with a TTL value of 2?16a.) A router will discard a packet if the Time to Live (TTL) value in an arriving packet is ______.a. 0b. 1c. 254d. 256b. What
a. Distinguish between application message fragmentation and packet fragmentation.b. Under what circumstances would the identification, flags, and fragment offset fields be used in IP?15b.) The
a. What is the main version of the Internet Protocol in use today?14a.) The main version of Internet Protocol in use today is IP version _______.a. 1b. 4c. 5d. 6b. Which IPv4 header component can be
An arriving packet has the destination IPv4 address 128.171.180.13. Row 86 has the destination value 128.171.160.0. The row’s mask is 255.255.224.0. Does this row match the destination IPv4
a. What should a router do if it receives several packets going to the same destination IPv4 address?12a.) If a router receives 20 packets in a row going to the same destination IP address, the
a. Distinguish between Step 2 and Step 3 in routing.11a.) Deciding what interface and to what device to send the packet back out is step _________ in the routing process.a. 1b. 2c. 3d. None of
a. Distinguish between Step 1 and Step 2 in the routing process.10a1.) The first step in the routing process involves _________.a. Selecting the best match rowb. Comparing the packet's destination IP
a. In Figure 8-11, how will a router test whether Row 3 matches the IPv4 address 60.168.6.7? Show the calculations in the format given in Figure 8-12. b. Is the row a match?c. Why is the last
a. In a routing table, what does a row represent?8a.) In a routing table, a _________ represents a route for a group of IP addressesa. Rowb. Columnc. Schemad. Metricb. Do Ethernet switches have a row
a. Why are routing tables more complex than Ethernet switching tables? Give a detailed answer.7a.) The Internet is organized in a ________.a. Hierarchyb. Ringc. Meshd. None of the above
a. A mask has eight 1s, followed by 0s. Express this mask in dotted decimal notation.6a.) In the mask 255.255.255.0, how many 1s are there?a. 8b. 16c. 24d. It cannot be determined from the
a. How many bits are there in an IPv4 mask?5a.) A mask has _____ bits.a. 8b. 16c. 32d. It cannot be determined from the information given.b. What do the 1s in an IPv4 network mask correspond to in
A router that has the routing table in Figure 8-11 receives an incoming IPv4 packet. The source IPv4 address in the arriving packet is 10.55.72.234. The destination IPv4 address is 10.4.6.7. The TTL
a. Connecting different networks is the main job of what type of router?4a.) A border router connects different IP ________.a. Sub-netsb. Networksc. Both A and Bd. Neither A nor Bb. What type of
A client PC has two simultaneous connections to the same web-server application program on a web-server. (Yes, this is possible, and in fact, it is rather common.) What will be different between the
a. What are the three parts of an IPv4 address?3a.) Which of the following is one of the three parts of an IPv4 address?a. Sub-net partb. Sub-net maskc. Both A and Bd. Neither A nor Bb. How long is
a. What are interfaces?2a.) Router sockets for wire and optical fiber cords are called ______.a. Socketsb. Plugsc. Interfacesd. Portsb. Explain the network adage “Switch where you can; route where
a. How does the postal service use hierarchical sorting?b. How does this simplify delivery decisions?
a. Which two layers standardize Ethernet and Wi-Fi operation?1a.) Ethernet standards are set at the ______.a. Physical layerb. Transport layerc. Both A and Bd. Neither A nor Bb. Which two layers
a. Why is a short transmission range not a protection against eavesdroppers?21a.) In IoT device transmission, published distance limits are relevant for _______.a. Legitimate usersb. Hackersc. Both A
a. What kind of network is Zigbee used for?20a.) Zigbee is designed to be used in a(n) ______ networkb. One-to onec. Hierarchicald. Multi-pointe. ad hocb. Compare the roles of Zigbee controllers,
a. How is the access point used in Wi-Fi Direct?19a.) Wi-Fi direct ______uses access points.a. Alwaysb. Usuallyc. Rarelyd. Never
a. When two devices communicate using NFC, how close must they be?18a.) When two devices communicate using NFC, how close must they be?a. A few inchesb. Up to 5 feetc. Up to 10 feetd. Up to 50 feetb.
a. What is a typical speed, distance, and power consumption for Bluetooth LE slaves?17a.) Bluetooth LE ________.a. Uses about 0.1 to 0.5 wattsb. Assumes that transmissions will be infrequentc. Has
a. Why would it be nice if Wi-Fi offered a basic printing profile?16a.) If Wi-Fi supported the basic printing profile, ________.a. Documents could be printed without downloading driversb. Printer
a. What does it mean that Bluetooth uses one-to-one operation?15a.) Bluetooth uses _______ operation.a. All-to-allb. Point-to-multi-pointc. One-to-alld. One-to-oneb. Is this still true if a master
a. What is a PAN? (Do not just spell out the abbreviation.)14a.) A group of devices on a desk that communicate wirelessly is called a _________.a. LANb. WANc. MANd. PANb. Compare the relative
a. Why is low speed and short distance usually good in the Internet of Things?13a.) IoT transmissions usually involve _______.a. High transmission speedsb. Low transmission distancesc. Both A and Bd.
a. Fill in the missing values in 7-16 Approximate, without using Excel, the decibel value for a ratio ofb. 8:1. Fill in the missing values in 7-16 Approximate, without using Excel, the decibel value
a. The power level at 10 meters is 100 mW. At 20 meters, it is 5 mW. How many decibels has it lost?11a.) Which is the correct formula for decibels?a. 10 × P2/P1b. 10 × (P2/P1)2c.
a. How might a security administrator use SNMP Get commands to access points?10a.) A security might use SNMP Get commands to _______.a. Change an access point’s powerb. Vollect information to look
a. Describe the process by which access point locations are determined.9a.) Selecting locations for access points first involves _______.a. Laying out circles of a chosen diameter in a diagram of the
a. What kind of physical device is an evil twin access point?8a1.) An evil twin access point is usually _______.a. A reprogrammed access pointb. A laptop computerc. A rogue access pointd. Any of the
a. Who creates a rogue access point?7a1.) An unauthorized internal access point is a(n) ______ access point.a. Evil twinb. Shadowc. Rogued. None of the above7a2.) A rogue access point usually is
a. What initial authentication mode does 802.11i use? 6a.) What initial authentication mode does 802.11i use?a. 802.1Xb. PSKc. Both A and Bd. Neither A nor Bb. Which initial authentication mode
a. Contrast the use scenarios for initial authentication in P S K mode and 802.1X mode.5a.) If a firm has many access points, it should use _________ initial authentication mode in 802.11i.a. PSKb.
Create a policy for 802.11 Wi-Fi security in a wireless network in a five-person company with one access point. This is not a trivial task. Do not just jot down a few notes. Make it a one-page
a. For what use scenario was 802.11i PSK initial authentication mode created?b. What must a user know to authenticate his or her device to the access point?4b.) In 802.11i _________, hosts must know
(If you read the box, “Expressing power ratios in decibels”)a. If you are told that a signal has attenuated by 20 dB, about how much has it attenuated?b. What would you say about attenuation
a. For what use scenario was 802.11i PSK initial authentication mode created?3a.) 802.11i PSK initial authentication mode was created for _______a. Corporations with multiple access pointsb.
a. A straight road with government-provided Internet will receive 16 access points that are 10 meters apart. About how many access points would be needed if the city decided to increase the distance
a. What cryptographic protections does 802.11i provide?2a.) 802.11i provides ________.a. Confidentialityb. Message integrityc. Both A and Bd. Neither A nor Bb. How is this protection limited?2b.) In
In the Ms. Betsy Davis case at the beginning of the chapter, the access point on the local network did not have security. This makes a man-in-the-middle attack much easier. a. Given what you
a. Do public hot spots protect your transmissions?a1.) Nearly all public Wi-Fi hot spots encrypt your transmissions.a. Trueb. Falseb. What type of attack did Ms. Davies use?c. How long did it take
a. What is the main promise of 802.11ax over 802.11ac?28a.) What is the main promise of 802.11ax over 802.11ac?a. Higher speedb. The ability to serve more usersc. MIMOd. Mu-MIMOb. Why is the 60 GHz
a. Why does the Wi-Fi Alliance release compatibility testing profiles in waves instead of combining the entire standard’s features initially?27a1.) An 802.11ac Wi-Fi compatibility testing profile
a. You are considering a laptop computer that uses 802.11ay. (802.11ay is discussed in the next subsection.) Will your existing 802.11ac access point be able to communicate with the new device?26a.)
a. What is beam forming?25a.) Beam forming can allow an access point to ________.a. Focus power on individual clientsb. Send signals to two different clients at the same timec. Both A and Bd. Neither
a. How does MIMO use spatial streams to increase transmission speed?24a.) MIMO _______.a. Bonds two or more channels for higher speedb. Is used in all forms of 802.11c. Uses a single spatial stream
a. You are using an access point with a rated speed of 4 Gbps. Why will you experience much less speed?23a.) Individual throughput for users of an access point _________.a. Depends on how many users
a. Compare the rated speeds of 802.11n and 802.11ac.22a.) Among the two most widely used 802.11 transmission standards today is _______.a. 802.11gb. 802.11acc. Both A and Bd. Neither A nor Bb.
a. If you triple channel bandwidth in a service band, approximately what happens to the number of channels in a service band?21a.) Wider channel bandwidth __________.a. Increases transmission speedb.
a. Describe RTS/CTS.20a.) In ________, when a wireless host wishes to send, it first sends a message to the wireless access point asking for permission to send. When the access point sends back a
a. What does CS mean? (Do not just spell out the abbreviation.)19a.) In CS MA/CA, CS means __________.a. Cancel sendingb. Counter-sourcec. Carriage suspensiond. Carrier senseb. How is
a. All wireless hosts and the access point that serves them transmit on the same channel. What problem does this cause?18a.) There is an access point that serves eight wireless hosts. On how many
a. What is roaming in 802.11?17a1.) A single access point and the set of hosts it serves is called a(n) _______.a. BSSb. BSSIDc. ESSd. None of the above17a2.) In roaming, a wireless client moves from
a. Why must an access point remove an arriving packet from the frame and place the packet in a different frame when it sends the packet back out?16a.) Access points take __________ from wireless
a. What spread spectrum transmission method dominates today?15a.) Which of the following uses O F D M ?a. 802.11acb. 802.11nc. Both A and Bd. Neither A nor Bd. Why does it divide
a. In the 2.4 GHz and 5 GHz service bands, what type of transmission method is required by regulators?14a.) Spread spectrum transmission is used in WLANs because _______.a. It is required
a. In what two unlicensed service bands does 802.11 usually operate?13a.) 802.11 operates in the _______ unlicensed service band.a. 2.4 MHz b. 60 MHz c. Both A and Bd. Neither A nor Bb. How
a. In Figure 6-12, there are question marks between several pairs of access points. For each of these pairs, list their channels of operation and whether they will interfere.12a.) Two access points
a. Do WLANs today use licensed or unlicensed service bands?11a1.) WLANs normally use __________.a. Licensed bandsb. Unlicensed bandsc. Both A and Bd. neither A or B11a2.) Many 802.11
a. Does a signal travel at a single frequency, or does it spread over a range of frequencies?10a.) Signals in a transmission usually _________.a. Travel at a single frequencyb. Spread over a range of
a. Distinguish among the frequency spectrum, service bands, and channels.9a1.) The frequency spectrum extends __________.a. Into the gigahertz rangeb. Into the visible light rangec. Into the
a. Contrast inverse square law attenuation and absorptive attenuation.8a.) What propagation problem is especially bad in moist air?a. Absorptive attenuationb. Electromagnetic interferencec. Multi
a. If you quadruple propagation distance, how much will signal intensity change at the receiver?7a.) At 10 meters, a signal has a strength of 100 mW. About how strong will it be at 40 meters?a. About
a. Distinguish between omnidirectional and dish antennas in terms of operation.b. Under what circumstances would you use an omnidirectional antenna?6b.) The other wireless device is near but in an
a. What is a transceiver?b. Is wireless radio transmission usually described in terms of wavelength or frequency?5b.) Wireless radio transmission speed is usually measured in terms of _______.a.
a. In 802.3 Ethernet networks, can simple installation rules usually reduce propagation effects to non-issues?4a.) Compared to wired transmission, propagation problems in radio transmission are
You have been using your phone and your school’s Wi-Fi network to access hosts on the Internet. Suddenly, you cannot reach Internet hosts. Create a two-column table. a) In the first column, create
a. In a Wi-Fi LAN, do two wireless hosts usually send frames directly to one another? Explain.3a.) In a Wi-Fi LAN, wireless hosts generally send frames directly to one another.a. Trueb. Falseb. Why
You can transmit 1.54 Gbps in a channel you use frequently. You want to transmit at 4.32 Gbps. How much wider must your channel be than its current bandwidth?
a. Distinguish between 802.3 standards and 802.11 standards.2a.) Wi-Fi Standards come from the _________ Working Group.a. 802.1b. 802.3c. 802.11d. 802.1Xb.What is the actual difference between
a. What do physical layer standards governb. What do data link layer standards govern?For the following lettered question parts, say whether the concept is a Layer 1 concern or a Layer 2
a. At what layers do wireless LANs operate?1a.) Wireless network standards operate at ________.a. The data link layerb. The Internet layerc. Both A and Bd. Neither A nor Bb. Do wireless LAN
Why might a company decided to use 80 MHz channels in 802.11ac instead of 160 MHz channels?
a. Before the attack, where does the ARP cache tell the victim to send a frame carrying a packet to the router?26a.) The ARP cache gives the _______ of a router the host will send a packet to.a. IP
a. What type of attack does 802.1A E protect against?25a.) To prevent an unauthorized user from sending supervisory commands to switches, companies use _____.a. 802.1Xb. SNMPc. VLANsd. 802.1AE
a. What security threat is 802.1X designed to protect against?24a.) To prevent anyone from simply walking up to a corporate switch and plugging their computer into its Ethernet port, companies can
a. What is the security benefit of Ethernet VLANs?23a.) Which of the following provides security in Ethernet?a. RSTPb. SNMPc. VLANsd. All of the aboveb. In Figure 5-28, to which hosts can Host D4…
a. What reliability problem does Ethernet have?22a.) Ethernet has reliability issues because of its _______.a. Too-simple switch operationb. Hierarchical organizationc. Both A and Bd. Neither A nor
a. What protocol do companies use to manage their Ethernet networks?12a.) To manage their Ethernet networks, companies rely on ______.a. SNMPb. HTTPc. FTTHd. None of the aboveb. What are manageable
a. What information do the two tag fields give?20a.) The two tag frames provide information about ______.a. Transmission mediab. The length of Jumbo packetsc. Priorityd. All of the aboveb. When is
a. Are Ethernet EUI-48 addresses expressed in hex for humans, devices, or both?19a.) EUI-48 addresses in expressed in hexadecimal notation if used by ______.a. Switchesb. Routersc. Both A and Bd.
a. What is the benefit of having a single possible path through an Ethernet network?18a.) Having only a single possible path between devices ______.a. Reduces switching costsb. Provides reliabilityc.
a. How are switches in an Ethernet LAN organized?17a.) In Ethernet, switches are organized in a _____.a. Ringb. Meshc. Hierarchyd. Any of the aboveb. Because of this organization, how many possible
a. Do switches know the entire data link between the source and destination host?16a.) A switch knows the entire data link between the source and destination hosts.a. Trueb. Falseb. What does a
a. Are the maximum distances for UTP and optical fiber transmission shown in Figure 5-12 and Figure 5-16 distance limits for physical links or data links?15a1.) At what layer is the 100BASE-TX
a. Compare relative cost and maximum propagation distance for multimode and single-mode fiber.14a.) Fiber that has a core diameter of 8.3 microns is _______.a. Multimode fiberb. Single-mode fiberc.

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