Question 1
Question
In version field of IPv4 header, when machine is using some other version of IPv4 then datagram is
Answer
-
Rejected
-
Accepted
-
Interpreted
-
Interpreted incorrectly
Question 2
Question
Network layer at source is responsible for creating a packet from data coming from another
Answer
-
Station
-
Link
-
Node
-
Protocol
Question 3
Question
Header of datagram in IPv4 has
Answer
-
0 to 20 bytes
-
20 to 40 bytes
-
20 to 60 bytes
-
20 to 80 bytes
Question 4
Question
An IPv4 datagram can encapsulate data from several higher-level protocols such as UDP, ICMP, IGMP and
Answer
-
TCP protocols
-
CDM protocols
-
ATM protocols
-
IEEE protocols
Question 5
Question
To record Internet routers of IPv4, that handles datagram is responsibility of
Answer
-
Record protocol
-
Record Data
-
Record Route
-
Record Header
Question 6
Question
Internet has chosen datagram approach to switching in the
Answer
-
Data Link Layer
-
Network Layer
-
Physical Layer
-
Presentation Layer
Question 7
Question
In IPv4 protocol, each datagram is handled
Answer
-
Independently
-
Dependently
-
Priority basis
-
Systematically
Question 8
Answer
-
Close Circuit Transmission
-
Congestion Controlled Traffic
-
Congestion Controlled Transmission
-
Close Circuit Traffic
Question 9
Question
Communication between a computer and a keyboard involves ______________ transmission
Answer
-
Automatic
-
Half-duplex
-
Full-duplex
-
Single direction
Question 10
Question
Three or more devices share a link in ________ connection
Answer
-
Unipoint
-
Multipoint
-
Point to point
-
None
Question 11
Question
In asynchronous serial communication the physical layer provide
Question 12
Question
The physical layer is responsible for
Answer
-
line coding
-
channel coding
-
modulation
-
all of the mentioned
Question 13
Question
A single channel is shared by multiple signals by
Answer
-
analog modulation
-
digital modulation
-
multiplexing
-
none
Question 14
Question
Wireless transmission can be done via
Answer
-
radio waves
-
microwaves
-
infrared
-
all of the mentioned
Question 15
Question
Which is not a application layer protocol?
Question 16
Question
The packet of information at the application layer is called __________
Answer
-
Packet
-
Message
-
Segment
-
Frame
Question 17
Question
Which one of the following is an architecture paradigms?
Question 18
Question
Application layer offers _______ service
Question 19
Question
E-mail is _________
Question 20
Question
To deliver a message to the correct application program running on a host, the _______ address must be consulted
Question 21
Question
Layers four and five of the Internet protocol stack are implemented in the end systems but not in the routers in the network core
Question 22
Question
With ADSL, each subscriber gets more downstream bandwidth than upstream bandwidth
Question 23
Question
Two packets A and B are sent in that order through a connection-oriented communication network. They could arrive at the destination:
Answer
-
in any order, after having traversed the same route.
-
only in the order A-B, after possibly having traversed different routes.
-
in any order, after possibly having traversed different routes
-
only in the order A-B, after having traversed the same route.
Question 24
Question
Two packets A and B are sent in that order through a connectionless communication network. They will arrive at the destination:
Answer
-
in any order, after possibly having traversed
-
in the order A-B, after having traversed the same route
-
in any order, after having traversed the same route.
-
in the order A-B, after possibly having traversed different routes
Question 25
Question
The Internet received its name in the 1980s because:
Answer
-
it was an interim (temporary) design of what it later became, but the name stuck.
-
it was meant to be a network internal to the United States Department of Defense.
-
it consisted of many interconnected networks.
-
it achieved international scope with the addition of the City University of London.
Question 26
Question
All store-and-forward networks are
Question 27
Question
When a student in Hong Kong uses her computer to have a voice conversation with a teacher in Pittsburgh, the application she uses requires that the network deliver bits at a modest but constant bit rate. This is because, even though voice can be faithfully encoded in less than 64 Kbps, the late arrival of a voice sample produces a noticeable and unpleasant sound effect. Which of the following switching options will give you better quality?
Answer
-
Packet-switched
-
Message-switched.
-
Space-switched.
-
Circuit-switched
Question 28
Question
The Date: header in the HTTP response message indicates when the object in the response was last modified.
Question 29
Question
The process that sends messages into, and receives messages from, the network through a software interface is called a socket.
Question 30
Question
The transfer of an html file from one host to another is:
Answer
-
loss-tolerant and time sensitive
-
loss-intolerant and time sensitive.
-
loss-intolerant and time insensitive.
-
none of the above
Question 31
Question
A browser will generate header lines as a function of
Answer
-
browser type and version.
-
user configuration of browser.whether the browser has a cached version of the requested object.
-
whether the browser has a cached version of the requested object.
-
all of the above
Question 32
Question
SMTP is used to:
Answer
-
to transfer messages from one mail server to another
-
to transfer messages from mail server to a user agent.
-
to define the format of message headers.
-
all of the above.
Question 33
Question
DNS resource record has Type=MX. Then:
Answer
-
Value is the hostname of the DNS server that is authoritative for Name.
-
Value is the IP address of the mail server that has the alias hostname Name.
-
Value is the hostname of the mail server that has the alias hostname Name.
-
none of the above.
Question 34
Question
Local DNS name servers:
Answer
-
cache resource records, but discard them after a period of time that is on the order of a few days
-
cache resource records and never discard them.
-
obtain resource records from Web caches.
-
never cache resource records
Question 35
Question
Consider an HTTP Web server using persistent connections. Suppose the server spawns a separate process for each client that connects to the server. Then each of these spawned processes will have different server port numbers.
Question 36
Question
The size of the TCP RcvWindow never changes throughout the duration of the connection
Question 37
Question
The TCP segment has a field in its header for RcvWindow
Question 38
Question
Suppose host A sends host B one segment with sequence number 38 and 4 bytes of data. Then in this same segment the acknowledgement number is necessarily 42
Question 39
Question
The MSS is the maximum size of a TCP segment including headers
Question 40
Question
When a TCP segment arrives to a host, the socket to which the segment is directed depends on
Question 41
Question
UDP has which of the following characteristics
Question 42
Question
When a UDP segment arrives to a host, in order to direct the segment to the appropriate socket, the OS uses
Question 43
Question
The stop-and-wait protocol is highly inefficient when there is a
Answer
-
large distance between source and destination and the transmission rate is low
-
short distance between source and destination and the transmission rate is high
-
large distance between source and destination and the transmission rate is high
-
short distance between source and destination and the transmission rate is low
Question 44
Question
Pipelining requires which of the following
Answer
-
transmitting many packets before receiving acknowledgements
-
unique sequence numbers for each in-transit packet
-
sender-side buffering of unacknowledged packets
-
all of the above
Question 45
Question
Suppose a client sends an HTTP request message with the If-modified-since: header. Suppose the object in a server has not changed since the last time a client retrieved the object. Then the server will send a response message with the status code
Answer
-
404 Not Foun
-
200 OK
-
304 Not Modified
-
none of the above
Question 46
Question
Streams are not needed in which of the following programs
Answer
-
TCPserver
-
UDPserver
-
TCPclient
-
UDPclient
Question 47
Question
For BitTorrent, which of the following is true
Answer
-
Although a peer may have 50 concurrent TCP connections with other peers, at any given instant of time it sends data to less than 10 other peers.
-
At a given instant of time, a peer A may upload to a peer B, even if peer B is not sending anything to A.
-
Among the chunks that a peer does not have, the peer will request chunks that appear to be relatively rare in the torrent.
-
All of the above
Question 48
Question
Consider the latency model for dynamic congestion windows. Which of the following components contribute to latency?
Question 49
Question
TCP applies fast retransmit to a segment when
Answer
-
it estimates unusually large RTTs
-
it receives three ACKs for an earlier segment
-
the segment's timer expires
-
none of the above
Question 50
Question
Nmap is often used to
Answer
-
do port scans over a range of ports at a target host
-
measure throughput between hosts
-
measure round-trip times between hosts
-
decipher encrypted traffic
Question 51
Question
With SYN cookies, when a server receives a SYN segment, it returns a SYNACK with
Answer
-
an initial sequence number that is a hash of the IP addresses and port numbers in the SYN segment (as well as of other things)
-
initial sequence number 1
-
a randomly chosen initial sequence number
-
none of the above
Question 52
Question
Before sending a packet into a datagram network, the source must determine all of the links that packet will traverse between source and destination
Question 53
Question
The primary role of a router is to forward datagrams from input links to output links
Question 54
Question
A forwarding table is
Answer
-
Used to find the proper interface to which the input interface should forward a packet
-
Configured using a centralized routing algorithm
-
Configured through routing protocol messages received by router
-
A and C
-
B and C
Question 55
Question
How are routing paths calculated?
Answer
-
The full route is mapped out in the datagram’s header.
-
Paths are calculated by routing algorithms.
-
Datagrams always flow on the same path and don’t need to be calculated.
-
The path is calculated based on available network bandwidth
Question 56
Question
A channel partitioning protocol has which of the following characteristics forwarding table is
Question 57
Question
Match the following network service to the correct definition
Answer
-
Guaranteed Delivery - Guarantees a packet will arrive at its destination
-
Guaranteed Delivery with Bounded Delay- Guarantees delivery within a specified host-to-host delay bound
-
Guaranteed Maximum Jitter - Guarantees the amount of time between the transmission of two successive packets at the sender is
equal to the amount of time between their receipt at the destination.
-
Я НЕ ЗНАЮ КАК ДОБАВИТЬ DROP DOWN ВОПРОС ПОЭТОМУ ПРОСТО ЗАПОМНИ ORDER
Question 58
Question
An ARP query packet is encapsulated in an IP datagram.
Question 59
Question
Ethernet provides which of the following services to the network layer
error detection
Answer
-
error detection
-
flow control
-
reliable data transfer
-
all of the above
Question 60
Question
For Ethernet, if an adapter determines that a frame it has just received is addressed to a different adapter
Answer
-
it discards the frame without sending an error message to the network layer.
-
it discards the frame and sends an error message to the network layer.
-
it sends a NACK (not acknowledged frame) to the sending host.
-
it delivers the frame to the network layer, and lets the network layer decide what to do
Question 61
Question
A beacon frame sent by an AP includes
Question 62
Question
Packets sent by two stations in 802.11 can collide because
Answer
-
at a given time, the random backoff values of the two stations are the same.
-
the packets are sent to different APs but on the same channel.
-
the two stations could be hidden from each other.
-
all of the above
Question 63
Question
An 802.11 frame includes
Question 64
Question
Which of the following statements best describes the purpose of the SNMP protocol?
Answer
-
The SNMP protocol specifies the actions a network manager should take in response to a specific set of network fault conditions.
-
The SNMP protocol is a tool for gathering data about network conditions and executing remote actions at remote managed devices.
-
The SNMP protocol is used by the network manager to provision resources, such as bandwidth, server capacity and other computational/communication resources needed to meet the mission-specific needs of an enterprise
Question 65
Question
What is the purpose of the SNMP SetRequest message?
Answer
-
To allow a managed device to request and receive a set of initial values for MIB objects in the managed device.
-
To allow a managing entity to query the value of a set of MIB object values in a managed device.
-
To allow a managing entity to set the value of one or more MIB objects in a managed device
Question 66
Question
What is the purpose of a presentation service?
Answer
-
To allow a client to inform a server that it (the client) is present and ready to receive data.
-
To encode, transmit, and translate data from one machine-specific format to another.
-
To display data in a format specified by a user.
-
None of the above
Question 67
Question
Filtering in a firewall can be based on:
Question 68
Question
How we call the link-layer packets?
Answer
-
Frames
-
Packets
-
Datagrams
-
Segment
-
Message
Question 69
Question
What is the segment?
Answer
-
application-layer packet
-
network-layer packet
-
data-link-layer packet
-
transport-layer packet
-
physical-layer packet
Question 70
Question
Most packets use these as the inputs to the links. This means that the packet switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link
Answer
-
Queuing delays
-
Store-and-forward
-
Reliable data
-
Datagram
Question 71
Question
The housing a large number of hosts, is often used to create a powerful virtual server
Answer
-
Supercomputer
-
Data center
-
Server house
-
Host center
Question 72
Question
Match the following delays to the correct definition
Answer
-
Processing delay
The time required to examine the packet’s header and determine where to direct the packet
-
Queuing delay
Packet waits to be transmitted onto the link
-
Transmission delay
This is the amount of time required to push all of the packet’s bits into the link
-
Propagation delay
Once a bit is pushed into the link, it needs to be spread to router
-
просто запомни ))))
Question 73
Question
________________ is a repository of information linked together from points all over the world
Question 74
Question
In a URL, the _______ is the full name of the file where the information is located
Question 75
Question
A cookie is made by the ________ and eaten by the _______
Answer
-
Client; client
-
Client; sever
-
Sever; server
-
None
Question 76
Question
In HTTP, the first line in a request message is called a _______ line; the first line in the response message is called the ________ line
Answer
-
Request; response
-
Response; request
-
Response; status
-
Header line; request
-
None
Question 77
Question
DNS provides a few other important service in addition to translating hostnames to IP addresses
Answer
-
Host aliasing
-
Delaying the packets
-
Congestion control
-
Load distribution
-
Mail server aliasing
Question 78
Question
Small piece of data sent from a website and stored in the user's web browser while the user is browsing
Answer
-
Web cache
-
Set-cookies
-
Cookies
-
Status line
Question 79
Question
A network entity that satisfies HTTP requests on the behalf of an origin Web server
Answer
-
Web browser
-
Client
-
Root servers
-
Data center
-
Proxy server
-
DNS servers
Question 80
Question
How many ports can be per IP address
Answer
-
65,535
-
68,535
-
65,335
-
64,535
-
60,535
Question 81
Question
FTP is built on _____ architecture
Answer
-
Client-server
-
P2P
-
Both of the mentioned
-
None
Question 82
Question
FTP uses _____ parallel TCP connections to transfer a file
Question 83
Question
If 5 files are transfered from server A to client B in the same session. The number of TCP connection between A and B is
Question 84
Question
The password is sent to the server using _____ command
Answer
-
PASSWD
-
PASS
-
PASSWORD
-
None
Question 85
Question
Time it takes for a small packet to travel from client to server and then back to the client
Question 86
Question
____________is a physical-layer device that acts on individual bits rather than frames
Answer
-
A hub
-
A host
-
Switch
-
Router
Question 87
Question
Define to which level of the network protocols are belong to
Answer
-
IMAP,POP3, DNS, FTP, Telnet-Application layer
-
TCP, UDP-Transport layer
-
ICMP, RIP, IPv4, IPv6-Network layer
-
ARP, ATM, Token ring-Data Link layer
-
Bluetooth, 802.11-Physical layer
-
ПРОСТО ЗАПОМНИ ВСЕ
Question 88
Question
___________algorithm computes the least-cost path between a source and destination using complete, global knowledge about the network
Answer
-
Virtual circuit
-
A global routing
-
Forwarding
-
None
Question 89
Question
Computer networks that provide only a connection service at the network layer are called
Answer
-
Datagram network
-
Virtual-circuit networks
-
Network
-
None
Question 90
Question
Each time an end system wants to send a packet, it stamps the packet with the address of the destination end system and then pops the packet into the network
Answer
-
Virtual-circuit networks
-
Network
-
Datagram network
-
None
Question 91
Question
Determine the correct class of the following IP address: 93.44.123.184
Question 92
Question
Determine the correct class of the following IP address: 160.23.244.224
Question 93
Question
Convert the following IP address: 192.224.224.15 to the binary
Answer
-
11000000. 11100000. 11100000. 00001111
-
11001100.11000111.11100011. 00001111
-
01010110. 01111011. 00000001. 00000001
-
11000100. 00000101. 01111011. 11011101
Question 94
Question
Convert the following IP address: 93.44.123.184 to the binary
Answer
-
11001100.11000111.11100011. 00001111
-
01010110. 01111011. 00000001. 00000001
-
11000100. 00000101. 01111011. 11011101
-
01011101. 00101100. 01111011. 10111000
Question 95
Question
Convert the following IP address: 158.0.147.85 to the binary
Answer
-
11001100.11000111.11100011. 00001111
-
01010110. 01111011. 00000001. 00000001
-
10011110. 00000000. 10010011. 01010101
-
11000100. 00000101. 01111011. 11011101
Question 96
Question
set of rules that the sending of rules that the sending program must follow so that the Internecan deliver the data to the destination program is called
Question 97
Question
Below provided a typical HTTP response message. Let’s take a careful look at this response message
What three sections has HTTP response message?
Answer
-
What three sections has HTTP response message?
-
header lines, entity body, and then the URL structure.
-
an initial status line, entity body, conclusion.
-
an initial status line, six header lines, and then the entity body.
-
header lines, entity body, and then the response
Question 98
Question
Below provided a typical HTTP response message. Let’s take a careful look at this response message. It has three sections:
an initial status line, six header lines, and then the entity body
The entity body is the meat of the message—it contains.
Answer
-
the information about receiver
-
the status line indicates that the server is using HTTP/1.1 and that everything is OK
-
the information about all the destination of packet
-
the requested object itself (represented by data data data data data)
Question 99
Question
Below provided a typical HTTP response message. Let’s take a careful look at this response message. It has three sections: an initial status line, six header lines, and then the entity body
In this example, the status line.
Answer
-
In this example, the status line.
-
has the information about receiver
-
has the requested object itself (represented by data data data data data …)
-
has the information about all the destination of packet
-
indicates that the server is using HTTP/1.1 and that everything is OK
Question 100
Question
How does an operating system identify the application to which data coming in from the network should be relayed
Answer
-
By the protocol with which the data was sent
-
Only one application at a time is given access to the network.
-
By the port number carried by the transport protocol
-
By the file extension of the data
Question 101
Question
The IP address space is organized in a hierarchy (I) to make the routing task more scalable, (II) to decrease inefficient fragmentation of the address space (III) to give institutions managing local-area networks autonomous control over the assignment of addresses to computers
Answer
-
I and III only
-
II only
-
none
-
I only
Question 102
Question
Which of the following protocols are essential to the existence of the Traceroute tool? 1 IP, 2 ICMP, 3 TCP
Answer
-
I and III only
-
II only
-
II and III only
-
I only
Question 103
Question
A difference between routers and switches is that
Answer
-
switches connect only to hosts, whereas routers connect networks
-
switches hold IP routing tables only for only local subnets
-
routers parse, process, and modify IP headers
-
routers perform the same function as switches but the two are marketed in very different way
Question 104
Question
At which of the following layers of the OSI protocol stack can the Internet Control Message Protocol be implement. 1Network, 2transport, 3Data link
Answer
-
I or II
-
I only
-
II only
-
III only
Question 105
Question
How to understand the connection-oriented protocol?
Answer
-
means that before the client and server can start to send data to each other, they first need to handshake and establish a TCP connection
-
means that provide an application with one or more security services can also provide timing guarantees
-
offers a different set of services to the invoking applications
Question 106
Question
Layers four and five of the Internet protocol stack are implemented in the end systems but not in the routers in the network core
Question 107
Question
Twisted-pair cooper wire is no longer present in computer networks
Question 108
Question
Two packets A and B are sent in that order through a connectionless communication network. They will arrive at the destination
Answer
-
in any order, after possibly having traversed different routes.
-
in the order A-B, after having traversed the same route.
-
in any order, after having traversed the same route.
-
in the order A-B, after possibly having traversed different routes
Question 109
Question
Compared to the wired transmission, wireless transmission typically has _____ attenuation and _____ maximum distance
Answer
-
higher, longer
-
lower, shorter
-
lower, longer
-
higher, shorter
Question 110
Question
Which of the following features of Ethernet has not remained constant since the advent of the technology?
Answer
-
Protocol header format
-
Protocol addressing
-
Use of CSMA-CD control
-
Transmission bandwidth
Question 111
Question
Which of the following internet applications typically transmit(s) packets over Transmission Control Protocol (TCP)? I.FTP client II.Audio streaming III.Web browser
Answer
-
I, II, and III
-
II only
-
I and II only
-
I and III only
Question 112
Question
In order to maintain network stability while Transmission Control Protocol (TCP) probes for additional bandwidth, rate increases are _____, and rate decreases are _____
Question 113
Question
Network clients use well-known _____ numbers to contact well-defined network services, such as Telnet and DNS servers
Answer
-
accept
-
connect
-
listen
-
port
Question 114
Question
Multicast communication generally refers to data that is
Answer
-
sent from several hosts to one host simultaneously
-
relayed through multiple routers
-
relayed through multiple bridges
-
sent from one host to several hosts simultaneously
Question 115
Question
The Internet Protocol (IP) defines the _____ layer of the Internet protocol stack
Answer
-
application
-
transport
-
physical
-
network
Question 116
Question
The term packetization refers to the process of
Answer
-
reassembling network packets for consumption by an application
-
using a digital instead of an analog transmission medium
-
using an analog instead of a digital transmission medium
-
splitting a message into fragments for network transmission
Question 117
Question
Which of the following statements is (are) true of network protocols?\n I.A protocol is a set of rules that facilitate communication among network applications.\n II.Only a single protocol may govern any transmission
Answer
-
II only
-
I and II
-
None
-
I only
Question 118
Question
Which of the following is a protocol used for communication between a web server and a web browser?
Answer
-
FTP
-
Telnet
-
World Wide Web (www)
-
HTTP
Question 119
Question
Which of the following is a disadvantage of connection-based protocols?
Answer
-
Unreliable connections
-
High error rates
-
Small MTU sizes
-
High startup costs
Question 120
Question
On a network, the term authentication typically refers to the process of
Answer
-
ensuring that users remain anonymous
-
ensuring that packets sent through the Internet cannot be intercepted
-
computing the checksum of packets
-
verifying the identity of a sender or receiver
Question 121
Question
Which of the following is the network-layer protocol of the Internet?
Question 122
Question
Which of the following was designed to solve the problem of IP address space fragmentation?
Question 123
Question
Which of the following IP header fields provide simple error detection?
Answer
-
Fragmentation
-
Time to live
-
Type of service
-
Checksum
Question 124
Question
Which of the following maps IP addresses onto datalink addresses?
Answer
-
Domain Name System (DNS)
-
Simple Network Management Protocol (SNMP)
-
Classless Inter Domain Routing (CIDR)
-
Address Resolution Protocol (ARP)
Question 125
Question
Consider an application running on host cs.cmu.edu that wants to send a packet to host ee.cmu.edu. Assuming no information is cached, the send request on cs.cmu.edu will cause which of the following events to happen first?
Question 126
Question
Which of the following can be used by a router to report a dropped packet to the packet's sender?
Answer
-
Simple Network Management Protocol (SNMP)
-
Border Gateway Protocol (BGP)
-
Dynamic Host Configuration Protocol (DHCP)
-
Internet Control Message Protocol (ICMP)
Question 127
Question
Which of the following IP header fields is designed to prevent a packet from remaining indefinitely in a routing loop?
Answer
-
Checksum
-
Length
-
Fragmentation
-
Time to live
Question 128
Question
Which of the following allows a host to be assigned an IP address automatically?
Answer
-
The simple network management protocol (SNMP)
-
The domain name system (DNS)
-
The address resolution protocol (ARP)
-
The dynamic host configuration protocol (DHCP)
Question 129
Question
Which of the following network exploration tools can be used to determine information about possible paths between one network host and another?
Answer
-
Ping
-
Netstat
-
Nslookup
-
Traceroute
Question 130
Question
The time required to examine the packet's header and determine where to direct the packet is part of the
Answer
-
Processing delay
-
Queuing delay
-
Transmission delay
-
Propagation delay
Question 131
Question
How we call the delay, when packet waits to be transmitted onto the link
Answer
-
Processing delay
-
Queuing delay
-
Transmission delay
-
Propagation delay
Question 132
Question
This is the amount of time required to push all of the packet's bits into the link
Answer
-
Processing delay
-
Queuing delay
-
Transmission delay
-
Propagation delay
Question 133
Question
The protocols of the various layers are called ___________
Answer
-
protocol stack
-
protocol layers
-
protocol group
-
protocol models
Question 134
Question
Which of the following OSI layers converts the ones and zeroes to electrical signals and places these signals on the cable?
Answer
-
Physical layer
-
Transport layer
-
Network layer
-
Application laye
Question 135
Question
Which of the following is most likely to be a MAC address assigned to a NIC?
Answer
-
192.168.1.121
-
24.17.232.75
-
23.4F.17.8A.4C.10
-
713.555.1212
Question 136
Question
Which layer of the TCP/IP model involves routing?
Answer
-
Physical layer
-
Transport layer
-
Application layer
-
Network layer
Question 137
Question
How much data can a typical frame contain?
Answer
-
500 bytes
-
1500 bytes
-
1500 bits
-
1 megabyte
Question 138
Question
Which of the following best describes an IP address?
Answer
-
A unique dotted decimal notation burned into every NIC
-
A unique 48-bit identifying number burned into every NIC
-
A dotted decimal notation assigned to a NIC by software
-
A 48-bit identifying number assigned to a NIC by software
Question 139
Question
Andalyn says complete 48-bit MAC addresses are allocated to NIC manufacturers from the IEEE. Buster says the IEEE only assigns the first 24 bits to manufacturers. Carlos says the IEEE assigns only the last 24 bits to manufacturers. Who is correct?
Answer
-
Only Andalyn is correct.
-
Only Buster is correct.
-
Only Carlos is correct.
-
No one is correct
Question 140
Question
Host A is sending host B a large file over a TCP connection. Assume host B has no data to send to A. Host B will not send acknowledgements to host A because host B cannot piggyback the acknowledgement on data
Question 141
Question
A channel partitioning protocol has which of the following characteristics
Question 142
Question
Ethernet provides which of the following services to the network layer
Question 143
Question
Each LAN adapter has a unique LAN address
Question 144
Question
A channel partitioning has which of the following characteristics
Question 145
Question
IEEE standard ethernet CSMA/CD provides which of the following services to the network layer?
Answer
-
reliable data transfer
-
error detection
-
error correction
-
all
Question 146
Question
Before sending a packet into a datagram network, the source must determine all of the links that packet will traverse between source and destination
Question 147
Question
The Session layer communicates with which other layers
Answer
-
Application and Transport
-
Transport and Network
-
Transport and Presentation
-
Transport, Presentation and Network
Question 148
Question
application layer data is
Answer
-
message
-
frame
-
datagram
-
data
-
segment
Question 149
Question
Transport layer data is
Answer
-
message
-
frame
-
data
-
datagram
-
segment
Question 150
Question
Network layer data is
Answer
-
message
-
frame
-
datagram
-
segment
-
data
Question 151
Question
Link layer data is
Answer
-
message
-
frame
-
datagram
-
data
-
segment
Question 152
Question
HTTP persistent connection - multiple objects can be sent over single TCP connection between client, server
Question 153
Question
HTTP non- persistent connection - multiple objects can be sent over single TCP connection between client, server
Question 154
Answer
-
to transfer messages from one mail server to another
-
to transfer messages from one mail server to another user agent
-
to define the format of message headers
-
to transfer messages from one user to another
Question 155
Question
The transmission of high-quality, interactive voice and video over the current Internet is difficult because today's Internet
Answer
-
does not really have sufficient throughput
-
gives higher priority to bulk data transfers
-
uses connectionless protocols
-
is unable to guarantee minimum throughput or maximum latency for a given connection
Question 156
Question
The throughput of a network link for an HTTP session is measured in two ways. Measurement A is the total amount of data received by the browser, divided by the duration of the session. Measurement B is the total amount of data received by the operating system on behalf of the browser, divided by the duration of the session. Which of the following statements about A and B is true?
Answer
-
B is smaller than A
-
A is smaller than B
-
B is equal to A
-
B and A are not related
Question 157
Question
Ethernet (IEEE 802.3) is an example of
Answer
-
a standard developed by the International Telecommunications Union
-
a successful example of the Internet's strategy of developing standards through "rough consensus and running code"
-
a de facto standard later developed into a de jure standard
-
an a priori standard
Question 158
Question
A packet with no data is sent from host A to host B on an otherwise idle network. The packet is found to have taken 35 milliseconds to reach B. The incremental overhead to send an additional byte (usually called the "throughput") is estimated to be five microseconds by repeatedly measuring the transmission times of long packets. Approximately, how long will an eight Kbytes (8192 bytes) packet take to reach B when sent from A?
Question 159
Question
When the data link layer applies "framing" to the data to be transmitted, it
Answer
-
cuts out the headers from higher layer protocols before transmission
-
adds the protocol headers from higher layers to the data before it transmits it
-
inserts flags to draw attention to high-priority data within a transmission
-
enhances it with extra data that permits the receiver to synchronize with the sender
Question 160
Question
In a broadcast-based network, longer propagation delays
Answer
-
destroy the carrier, making it impossible to sense it before transmitting
-
make it all the more critical to sense the carrier before transmitting
-
significantly decrease the benefit of sensing the carrier before transmitting
-
do not affect the cost-benefit trade-off of carrier sensing
Question 161
Question
What is the type of an "8+1" parity code that outputs 100101011?
Question 162
Question
A specific CSMA-CD network such as 10-BASET "Ethernet
Answer
-
has higher cost per node as nodes are added
-
can connect very distant node
-
works best for an even number of nodes
-
suffers performance degradation as nodes are added
Question 163
Question
A university has 20 computers in a laboratory that is currently served by several small 10 Base-T "Ethernet" hubs that are directly connected to each other. The network performance has been found to be lacking, and an upgrade is planned. The computers are identical and place a comparable load on the network that is relatively constant and modest for each computer (in the order of 500 Kbps). What would you suggest for the upgrade?
Answer
-
A small 10 Base-T switch to connect the existing hub
-
Replace the hubs with 100 Base-T hub
-
A new bank of dial-up modems
-
Replace the hubs with 10 Base-T switches
Question 164
Question
A sender's data link layer uses "bit stuffing" to
Answer
-
force the receiver to enlarge its flow control window
-
avoid confusing data bits with control bits
-
pad the data so that it has an even length for parity calculations
-
mark the start and the end of a frame
Question 165
Question
The Internet Protocol (IP) is used in the network layer of the Internet. Which service does IP provide to the transport layer?
Answer
-
Connectionless service via virtual circuits
-
Connectionless service via datagrams
-
Connection-oriented service via datagrams
-
Connection-oriented service via virtual circuits
Question 166
Question
A corporate information systems manager is interested in collecting statistics on the frequency of computer failures within the organization. Most failures result in an automatic reboot, so the failed computer is typically back on the network in less than a minute. The corporate network connects 1,500 computers in far-flung locations to which the average latency of a packet is 40 milliseconds. The manager asks you to write a tool that will collect the times at which failures occurred in which computers. She wants it by tomorrow, so the tool will have to be simple. On which protocol will you base your implementation?
Question 167
Question
A router is installed to interconnect 4 subnetworks with MTUs of 1024, 2048, 576, and 1556 bytes respectively. Nodes A and B are connected to the first and second subnets, respectively. An application on node A sends a 4096-byte datagram (e.g., using UDP) to an application on node B. How many IP fragments will the router process as a result?
Question 168
Question
The network interface card of a Web server that you manage has developed sporadic problems. You measure the packet loss rate from your desktop computer and immediately decide to replace the network card. After this simple operation, the Web server successfully rejoins the network, as confirmed by your officemate using her desktop computer. You eagerly go to your desktop to measure the improvement, but find instead that the Web server is not responding to any of your packets. What is your diagnosis?
Answer
-
The new network card does not work.
-
Your desktop computer is still trying to contact the server's old network card.
-
Your desktop computer's network card does not work.
-
The Domain Name System (DNS) has not yet updated its entry for the Web server.
Question 169
Question
In contrast to standards developed by traditional standards organizations like the International
Telecommunications Union (ITU) or the International Standards Organization (ISO), standards developed by the Internet Engineering Task Force (IETF) can be
Answer
-
developed in secret by the members of the IETF until the standards mature sufficiently to withstand public criticism
-
modified arbitrarily by the Advance Research projects Agency (ARPA) of the United States Department of Defense, which originally developed the Internet
-
applied before they have been embodied in working implementations, in order not to delay progress
-
extensively critiqued and modified by individuals, without requiring them to have special membership status
Question 170
Question
there are transport service requirements, for which of the following applications these requirements are demanded: no data loss, elastic throughput, and not time sensitive
Answer
-
e-mail
-
real time audio/video
-
text messaging
-
games
Question 171
Question
there are transport service requirements, for which of the following applications these requirements are demanded: no data loss, elastic throughput, and not time sensitive
Answer
-
web documents
-
real time audio/video
-
text messaging
-
games
Question 172
Question
reliable transport between sending and receiving process refers to (protocol type)?
Question 173
Question
TP client contacts FTP server at port ______, using TCP
Question 174
Question
331 Username OK, password required – status code refers to (protocol type)?
Question 175
Question
e-mails use ______________ protocol for sending messages
Question 176
Question 177
Question 178
Question
Which of the following statements are true about the TCP service model?
Answer
-
TCP uses a checksum to determine if the application data follows the right syntax
-
TCP delivers a stream of bytes from one end to the other, reliably and in-sequence, on behalf of an application
-
Because TCP encodes data with enough information to correct errors, it never needs to retransmit missing segments
-
Because TCP cannot trust the IP layer to format packets correctly, it must include the destination IP address in the TCP header
-
TCP is responsible for providing reliable, in-sequence end-to-end delivery of data between applications.
Question 179
Question
Which of the following are direct consequences of this design choice?
Answer
-
TCP is self-contained with sufficient addressing information in its header that it does not need the IP layer, or any other layer beneath it to deliver data to the far end
-
TCP will retransmit missing data even if the application can not use it - for example, in Internet telephony a late arriving retransmission may arrive too late to be useful
-
TCP can only work correctly if the layer below it also delivers data reliably and in sequence
-
TCP requires no connection state to be established prior to the end points communicating
Question 180
Question
The _______ layer lies between the network layer and the application layer.
Answer
-
physical
-
data link
-
transport
-
none
Question 181
Question
Which of the following is an application layer service?
Answer
-
remote log-in
-
mail service
-
file transfer and access
-
all
Question 182
Question
The_________ layer is responsible for the delivery of a message from one process to another
Answer
-
physical
-
data link
-
transport
-
network
Question 183
Question
The Internetworking Protocol (IP) is a ________ protocol
Answer
-
reliable
-
connectionless
-
connection oriented
-
none
Question 184
Question
____ is a process-to-process protocol that adds only port addresses, checksum error control, and length information to the data from the upper layer
Question 185
Question
__________provides full transport layer services to applications
Question 186
Question
Translation of a domain name into an address called
Question 187
Question
In a link layer hosts and router are called
Answer
-
Node
-
Frame
-
Protocol
-
Server
Question 188
Question
Link layer encapsulates datagrad in a
Answer
-
Node
-
Frame
-
Protocol
-
Server
Question 189
Question
The FDDI protocol is based on
Question 190
Question
Registered users may look up all meetings in their agenda in a given interval of time
Answer
-
Querying Meetings
-
User Registration
-
Adding Meetings
-
Deleting Meetings
-
Clearing Meetings
Question 191
Question
Dividing the network into smaller portions called
Answer
-
Subnet
-
Subnet Mask
-
Bits
-
IP
Question 192
Question
Identify the incorrect statement
Answer
-
FTP sends its control information in-band
-
FTP stands for File Transfer Protocol
-
FTP uses two parallel TCP connections
-
FTP sends exactly one file over the data connection
Question 193
Question
Find the FTP reply whose message is wrongly matched
Answer
-
331 – Username OK, password required
-
425 – Can’t open data connection
-
452 – Error writing file
-
452 – Can’t open data connection
Question 194
Question
Typically the TCP port used by SMTP is
Question 195
Question
The entire hostname has a maximum of ___characters
Question 196
Question
Which one of the following allows a user at one site to establish a connection to another site and then pass keystrokes from local host to remote host?
Question 197
Question
All link layer protocols that support IP have the same frame structure (i.e., length of frame, number and length of header fields).
Question 198
Question
Suppose a network manager wanted to query the value of the number of TCP segments received by a host running the Microsoft Windows 2000 operating system in a US-based company. What would be the prefix (leading digits) of the MIB variable that should be queried?
Question 199
Question
For public-key certification, PGP uses certification authorities.
Question 200
Question
The 802.11 protocol does not implement collision detection because
Answer
-
the adapter would still not be able to detect all collisions due to hidden terminals.
-
it is costly to build wireless hardware that detects collisions.
-
collision detection was found to be useless in wired Ethernet.
-
all of the above