Question 1 From the following statements, select all that correctl...

Question 1
From the following statements, select all that correctly describe assigning addresses.
The address space of the IP protocol consists of 2 to the power of 24 (2^24) available addresses.
Each MAC address assigned by a network interface card (NIC) manufacturer is intended to be different from all other MAC addresses assigned by manufacturers throughout the world.
Each IPv4 address is assigned by a network interface card (NIC) manufacturer, and is intended to be different from all other IPv4 addresses assigned by manufacturers throughout the world.
A DHCP server always assigns the same IP address to the same computer whenever that computer requests an IP address.
A server's IPv4 address can be configured and assigned by a network engineer who creates a configuration file on that server.

Question 2
From the following statements, select all that correctly describe asynchronous transmission.
Asynchronous transmission protocols are always more efficient than synchronous transmission protocols.
With asynchronous transmission, the value of the start bit preceding a character and the value of the stop bit following a character must always be the same.
If each character in an asynchronous transmission protocol is encoded with 8 bits, one parity bit is used for error detection of that character, and one start and one stop bit is used to demarcate the character, then 11 bits per character would be transmitted using that protocol.
The purpose of the start bit in an asynchronous transmission protocol is to assist the receiver in recognizing an incoming character.
Asynchronous transmissions can be sent at irregular time intervals.

Question 3
Review the following scenario, which describes an instant messaging application, then follow the subsequent instructions.
An organization has developed an instant messaging application that enables its employees to collaborate in the organization's local area network which is a Gigabit Ethernet network. The application generates packets that are sent using TCP over IP over Ethernet. The length of each message generated by the application itself is 154 bytes.
Select all statements that correctly define the transmission efficiency and effective data rate of the application described in the scenario. For this scenario, you may assume that the header size for TCP is 20 bytes, IP is 20 bytes, and Ethernet is 26 bytes.
The transmission efficiency is equal to 80%.
The effective data rate is equal to 1Gbps.
The transmission efficiency is equal to 70%.
The effective data rate is equal to 800Mbps.
The effective data rate is equal to 700Mbps.

Question 4
Review the following scenario, which describes data link layer address resolution, then follow the subsequent instructions.
ComputerA and ComputerB are located on the same subnet in an organization's TCP/IP local area network (LAN). ComputerA needs to send a message to ComputerB. ComputerA knows ComputerB's IP address, but does not know ComputerB's MAC address.
From the following statements, select all that correctly describe the given scenario.
Before sending a message to ComputerB, ComputerA sends an ARP request only to a router, and the router responds with ComputerB's MAC address.
Before sending a message to ComputerB, ComputerA must first issue an ARP broadcast to obtain ComputerB's MAC address.
ComputerA can send a message directly to ComputerB without knowing ComputerB's MAC address.
After ComputerA learns ComputerB's MAC address, the MAC address is stored in ComputerA's address table for future use.
ARP packets used in this scenario are sent at the application layer.

Question 5
Imagine that all IPv4 addresses in an organization use 22-bit network identifiers. Given the following CIDR entries from the organization:
99.222.31.15/22
99.222.27.18/22
99.222.28.240/22
99.223.31.15/22
and the following IPv4 address in binary, which also has a 22-bit network identifier:
01100011 11011110 00011001 00001110
Select all statements that correctly describe which addresses are on the same network.
99.222.31.15/22 is on the same network as 99.222.28.240/22.
99.222.31.15/22 is on the same network as IPv4 address 01100011 11011110 00011001 00001110.
99.222.27.18/22 is on the same network as IPv4 address 01100011 11011110 00011001 00001110.
99.222.28.240/22 is on the same network as IPv4 address 01100011 11011110 00011001 00001110.
99.222.27.18/22 is on the same network as 99.222.28.240/22.
99.223.31.15/22 is on the same network as IPv4 address 01100011 11011110 00011001 00001110.
99.222.27.18/22 is on the same network as 99.223.31.15/22.
99.222.31.15/22 is on the same network as 99.222.27.18/22.
99.222.31.15/22 is on the same network as 99.223.31.15/22.
99.222.28.240/22 is on the same network as 99.223.31.15/22.


Question 6
Imagine that two (2) computers named Computer A and Computer B have only one network adapter each, and that both are connected to the same network. Further imagine that Computer A's IPv4 configuration is represented by the CIDR entry 25.242.251.45/22, and that Computer B's IPv4 configuration is represented by the CIDR entry of 25.242.252.102/24.
Select all true statements about this scenario.
a. Computer A's network identifier in binary is 0001100111110010111110.
b. Computer B's network address in dotted decimal notation is 25.242.252.0.
C. Computer A's network address in dotted decimal notation is 25.242.251.0.
d. Computer B's network identifier in binary is 000110011111001011111110.
e. Computer B's network identifier in binary is 000110011111001011111100.


Question 7
Imagine that two (2) computers named Computer A and Computer B have only one network adapter each, and that both are connected to the same network. Further imagine that Computer A's IPv4 configuration is represented by the CIDR entry 23.239.112.201/19, and that Computer B's IPv4 configuration is represented by the CIDR entry of 23.239.128.105/22.
Select all true statements about this scenario.
a. Computer A's subnet mask in dotted decimal notation is 255.255.224.0.
b. Computer A's subnet mask in binary notation is (00000000.00000000.00011111.11111111
C. Computer B's subnet mask in dotted decimal notation is 255.255.252.0.
d. Computer B's subnet mask in dotted decimal notation is 255.255.97.0.
e. Computer A's subnet mask in binary notation is 11111111.11111111.11100000.00000000


Question 8
From the options listed below, select all that correct errors by identifying errors and retransmitting the data.
Automatic Repeat Request (ARQ)
Repetition
Ethernet
Routing Information Protocol (RIP)
IPv4


Question 9
From the following statements, select all that correctly describe error detection in data transmissions.
With Cyclic Redundancy Check (CRC) error detection, the probability of detecting an error is 100% for all errors where the number of bits affected is greater than the number of overhead bits added to the message.
Error detection for a given protocol is typically implemented by including overhead containing extra data in each protocol data unit.
Parity checking is commonly used in networks today for error detection, because of its high error-detection rate.
If two bits are switched during transmission, parity checking will not detect that error.
A checksum is typically 1 byte of overhead added to the end of a message.


Question 10
From the following statements, select all that correctly describe error prevention.
a. White noise can be entirely avoided only if the signal strength is significantly increased.
b. Repeaters repeat digital signals to combat attenuation without amplifying the white noise on the circuit.
C. An amplifier used to combat signal attenuation can amplify an analog signal without amplifying the white noise that exists on the circuit.
d. The distance between two consecutive amplifiers depends on the amount of power loss per unit length of distance on the circuit.
e. Shielding cables or moving cables away from power sources may reduce impulse noise.

Question 11
From the following statements, select all that correctly describe the Internet Protocols IPv4 and IPv6.
All IPv6 addresses can be used without modification on all IPv4 networks.
IPv6 addresses are 128 bits in length, while IPv4 addresses are 32-bits in length.
The Internet version 4 (IPv4) has theoretical maximum of roughly 2^32 (2 to the power of 32) addresses.
IPv4 and IPv6 are data-link layer protocols.
IPv6 addresses are commonly represented in hexadecimal (base 16).


Question 12
From the following statements, select all that correctly describe Media Access Control.
The only approach to Media Access Control is controlled access, which controls the circuit and determines which devices can transmit at what time.
Collision detection is an important part of some protocols' media access control.
Contention is a method of Media Access control where devices wait until the circuit is free (no other devices are transmitting) before they transmit data over the circuit.
Media Access control is important in multipoint circuits where several computers share the same circuit.
Media Access Control is never useful on any point-to-point configuration.


Question 13
From the following statements, select all that correctly describe routing protocols.
If two autonomous systems communicate with each other via border routers, then both autonomous systems must use the same interior routing protocol.
The Border Gateway Protocol (BGP) can only be used as an interior routing protocol used inside autonomous systems on the Internet.
Routing Information Protocol (RIP) is best suited for large networks that have many possible routes.
When routers are configured to use a routing protocol, those routers exchange information with each other to help determine the best routes.
An exterior routing protocol is a routing protocol that is used to exchange routing information between routers that connect autonomous systems.


Question 14
Review the following scenario, which describes server name resolution, then follow the subsequent instructions.
Alisha works as a network engineer for Pineapple, a large IT corporation, and plans to apply for a master degree in Computer Science and Information Technology at Boston University's Metropolitan College (MET). During a lunch hour, Alisha decides to use her work computer to visit BU's web server, whose address is www.bu.edu, in order to review the master degree requirements and the courses offered. Pineapple has its own DNS server, known as PineDNS, which is only preconfigured with the DNS addresses of Pineapple's computers. No employee in Pineapple's network has ever before visited BU's website.
From the following statements, select all that correctly describe the given scenario.
Once Alisha enters BU's website in her web browser, Alisha's computer sends a DNS request to PineDNS requesting the IP address that corresponds to www.bu.edu.
When PineDNS receives a DNS request from Alisha's computer that requests the IP address corresponding to www.bu.edu, PineDNS responds to Alisha's computer with a DNS response that contains the desired IP address, without requesting additional information from other DNS servers.
When PineDNS receives a DNS request from Alisha's computer that requests the IP address corresponding to www.bu.edu, PineDNS issues a request to another DNS server outside of
Pineapple's network in order to determine the desired IP address.
As soon as Alisha's computer receives the IP address that corresponds to www.bu.edu, the IP address is stored in the DNS cache of Alisha's computer.
The DNS requests and responses exchanged between Alisha's computer and PineDNS bypass the transport and network layers, being sent directly at the data-link layer.


Question 15
From the following statements, select all that correctly describe sources of errors in data transmission.
Cross-talk, Impulse Noise, and Gaussian Noise are sources of errors that can occur on both digital and analog circuits.
Cross-talk occurs when a circuit erroneously picks up a signal from an outside source, such as another circuit, another wire, or another antenna.
Electrical media, such as twisted pair wire and coaxial cable, are more likely than are optical cable to suffer from line noise, which can cause data communication errors.
In general, errors are more likely to occur in transmission through cables, than through wireless, microwave, or satellite transmissions.
Intermodulation noise is a special type of cross-talk.


Question 16
From the following statements, select all that correctly describe Synchronous transmission.
a. Synchronous transmission can only be used on multipoint circuits.
b. With synchronous transmission, data is only transmitted as characters, and each character is transmitted independently each with start and stop bits to indicate the beginning and end of the character.
C. Ethernet is a synchronous transmission protocol that is commonly used in local area networks (LANs).
d. Using Synchronous transmission, data is transmitted in blocks called frames.
e. With Synchronous transmission, when used on a multipoint circuit, each frame must include a destination and a source address.


Question 17
From the following statements, select all that correctly describe the Transmission Control Protocol (TCP).
TCP segments contain the source and destination port identifier.
While many Transport Layer protocols exist in theory, all modern applications only use TCP.
A sender may have many active TCP connections with the same receiver at the same time.
TCP checks for out-of-order messages, but not for lost messages.
TCP segments contain a sequence number used to assemble segments into the correct order.


Question 18
Review the following scenario, which describes an application software for music streaming, then follow the subsequent instructions.
CoolServer is server software hosted in Caifornia that allows for the download of jazz music over the Internet. CoolServer requires the use of TCP over IP, and its port address is 5678.
CoolServer can be accessed via CoolClient, a desktop client application. Oscar is an avid jazz fan living in New York, and uses CoolClient to make a connection to CoolServer. Oscar's operating system assigns port 9989 to CoolClient for the connection.
From the following statements, select all that correctly describe the given scenario.
Messages originating from CoolClient over the connection must be encapsulated in a TCP segment whose destination port address is 5678 and whose source address is
5678.
CoolClient's messages to CoolServer are segmented at the transport layer, and the length of each segment is determined by TCP, which attempts to create a length of segment suitable for both IP and the data-link layer between CoolClient and CoolServer.
CoolServer may make use of two IP addresses by designating one address for incoming messages and another for outgoing messages, thus eliminating the need to use TCP ports on the connection.
Messages originating from CoolClient over the connection must be encapsulated in a TCP segment whose destination port address is 5678 and whose source address is 9989.
Once the connection is established, CoolServer can send response messages to CoolClient via the data link layer, avoiding the need for segmentation by TCP.

Question 19
Review the following scenario, which describes two applications used in an organization's network, then follow the subsequent instructions.
ConnectionOrientedApp is an application that uses connection-oriented messaging to exchange data between ConnectionOrientedApp clients and the ConnectionOrientedApp server that exist in an organization's IP network, while ConnectionlessApp is an application that uses connectionless messaging to exchange data between ConnectionlessApp clients and the ConnectionlessApp server in the same network. ConnectionOrientedApp's packets can be categorized into two distinct quality of service (QoS) classes, one for high priority traffic and another for low priority traffic.
CircuitX is a communication path in the organization's network that allows at most 100 simultaneous TCP connections with high priority ConnectionOrientedApp traffic.
From the following statements, select all that correctly describe the given scenario.
Quality of service (QoS) classes are only supported at the application layer, but not in any other layer in the Internet model.
A TCP connection between a ConnectionOrientedApp client and the ConnectionOrientedApp server is considered established after a successful three-way handshake.
Since ConnectionlessApp client and ConnectionlessApp server communicate in a connectionless manner, it is mandatory that the client and server establish a new TCP connection after every two or three messages.
The organization's network will not permit the establishment of high priority ConnectionOrientedApp connections through CircuitX whenever CircuitX has a total of 100 simultaneous connections with high priority ConnectionOrientedApp traffic.
Any three consecutive messages generated by a ConnectionlessApp client, that are destined for the ConnectionlessApp server, are guaranteed to follow the same communication path in the organization's network, and are guaranteed to arrive in sequence at the ConnectionlessApp server.


Question 20
Select all statements that correctly describe types of routing.
a. One advantage of dynamic routing is that the routing decisions are continuously updated to reflect the changing network conditions with the goal of selecting the best route in the network.
b. Link state routing protocols make routing decisions based only on the speed of the circuit of each route that exists in a network.
C. If the route defined between two routers that use static routing fails, the routers automatically revert to dynamic routing in order to build a new route between the routers.
d. One disadvantage of dynamic routing compared to static routing is that routers need to dedicate more computing resources to update their routing tables.
e. Static routing is a type of centralized routing, because the routes are manually defined by a network manager from a central management point in the network.