Cisco Network Fundamentals - Chapter 4

Front 1

Which characteristics are part of TCP? Pick two: Reliable, connectionless, no flow control, resends anything not received?

Back 1

Reliable, connection-oriented protocol (resends if not received)

Front 2

At the transport layer, which of the following controls is used to keep a transmitting host from overflowing the buffers of a receiving host? Choose one: Best effort, encryption, flow control, congestion avoidance?

Back 2

TCP uses flow control

Front 3

End systems use port numbers to select the proper application. What is the lowest port number that can be dynamically assigned by the host system? 1, 128, 256 or 1024?

Back 3

1024. The lower numbers are the well-known ports.1024 through 49151 are registered ports and used by the host for dynamic port allocation

Front 4

During data transfer, what is the receiving host responsible for? Choose two: Encapsulation, bandwidth, segmentation, acknowledgment, reassembly

Back 4

Acknowledgment and reassembly (receipt of packets and putting them in right order)

Front 5

What are the transport layer's responsibilities?

Back 5

Keeping track of the individual conversations taking place between applications on the source and destinations hosts,
Segmenting data and adding a header,
Using header info to reassemble the segments into application data,
Passing the assembled data to the correct application

Front 6

Why does TCP use a sequence number in the header?
A) To reassemble the segments into data
B) To identify the application layer protocol
C) To indicate the number of the next expected byte
D) To show the maximum number of bytes allowed during a session

Back 6

Allows the receiving host to reassemble segments in proper order

Front 7

Which of the following determines how much data a sending host running TCP/IP can transmit before it must receive an acknowledgment?

A) Segment size
B) Transmission rate
C) Bandwidth
D) Window size

Back 7

Window size is used to manage flow control

Front 8

What is the purpose of TCP/UDP port numbers?
A) To indicate the beginning of a three-way handshake
B) To reassemble the segments into the correct order
C) To identify the number of data packets that can be sent without acknowledgment
D) To track the different conversations crossing the network at the same time

Back 8

D, port numbers allow you to track multiple conversations generated by the same host using the same IP address

Front 9

What does segmentation provide to communications?

Back 9

Segmentation provides the means to send and receive data when running multiple applications concurrently on a computer

Front 10

In networking terms, what is reliability?

Back 10

It means ensuring that each segment that the source sends arrives at the destination

Front 11

List three network applications that use TCP

Back 11

web browsing, email, file transfer

Front 12

List three network applications that use UDP

Back 12

DNS, video-streaming, VoIP

Front 13

What is contained in the header of each segment or datagram?

Back 13

The source and destination port number

Front 14

What is the purpose of sequence numbers?

Back 14

Allows the transport layer function on the destination host to reassemble segments in the right order

Front 15

What is the protocol number for UDP?
1, 3, 6, or 17?

Back 15

17 (A flag is set in the segment header. If this flag actually reads 17, it is identified as a UDP header)

Front 16

What is the default DNS port number?
1025, 53, 110, or 143?

Back 16

53

Front 17

What is the netstat utility used for on a host?

Back 17

Netstat lists the protocols in use, the local address and port number, the foreign address and port number, and the state of the connection. Also displays active TCP connections, ports on which the computer is listening, Ethernet statistics, the IP routing table, Ipv4 statistics (for IP, ICMP,, TCP, and UDP) and Ipv6 statistics. Used without parameters, the netstat command displays active TCP connections.

Front 18

Which protocol provides just the basic functions for efficiently delivering data pieces between appropriate applications - TCP or UDP?

Back 18

UDP - it sends datagrams as "best effort"

Front 19

UDP stands for?

Back 19

User Datagram Protocol

Front 20

Which protocol ensures more reliable delivery between applications - TCP or UDP?

Back 20

TCP. It makes larger demands on a network

Front 21

Which is a connectionless protocol - UDP or TCP?

Back 21

UDP

Front 22

Port 20 is?

Back 22

FTP

Front 23

Port 23 is?

Back 23

Telnet

Front 24

Port 25 is?

Back 24

SMTP

Front 25

Which is a connection-oriented protocol - TCP or UDP?

Back 25

TCP

Front 26

How many bytes of overhead do TCP segments carry? How many does UDP carry?

Back 26

20 and 8

Front 27

Port 69 is?

Back 27

TFTP - Trivial File Transfer Protocol

Front 28

Port 110 is?

Back 28

POP3

Front 29

Port 194 is?

Back 29

IRC

Front 30

Port 443 is?

Back 30

HTTPS (Secure HTTP)

Front 31

Port 520 is?

Back 31

RIP (Routing Information Protocol)

Front 32

MSN messenger uses TCP or UDP?

Back 32

TCP

Front 33

Port 8080 is?

Back 33

An alternate HTTP port

Front 34

SYN is?

Back 34

Synchronize sequence numbers

Front 35

ACK is?

Back 35

Acknowledgment field significant

Front 36

The three-way handshake performs what three functions?

Back 36

That the destination device is there, figures out if it has an active service running and is accepting requests on the right port, tells the destination device that it wants to communicate on said port

Front 37

The value of the ACK number field is equal to the client ISN plus ___________ (number)?

Back 37

1

Front 38

When the client end of the session has no more data to transfer, it sets the ___________ flag in the header of the segment? (Hint: three-letter acronym)

Back 38

FIN

Front 39

UDP does or does not keep track of sequence numbers?

Back 39

Does not - TCP does

Front 40

UDP does or does not create a session?

Back 40

Does not