1
A PC is downloading a large file from a server. The TCP window is 1000 bytes. The server is sending the file using 100-byte segments. How many segments will the server send before it requires an acknowledgment from the PC?
1 segment
10 segments*
100 segments
1000 segments

2
A host device needs to send a large video file across the network while providing data communication to other users. Which feature will allow different communication streams to occur at the same time, without having a single data stream using all available bandwidth?
multiplexing *
window size
acknowledgments
port numbers

3
A technician wishes to use TFTP to transfer a large file from a file server to a remote router. Which statement is correct about this scenario?
The file is segmented and then reassembled in the correct order by TCP.
The file is not segmented, because UDP is the transport layer protocol that is used by TFTP.
Large files must be sent by FTP not TFTP.
The file is segmented and then reassembled in the correct order at the destination, if necessary, by the upper-layer protocol.*

4. Refer to the exhibit. Consider a datagram that originates on the PC and that is destined for the web server. Match the IP addresses and port numbers that are in that datagram to the description. (Not all options are used.)


192.168.1.2 -> source IP address
192.168.2.2 -> destination IP address
2578 -> source port number
80 -> destination port number

5
Which scenario describes a function provided by the transport layer?
A student is using a classroom VoIP phone to call home. The unique identifier burned into the phone is a transport layer address used to contact another network device on the same network.
A corporate worker is accessing a web server located on a corporate network. The transport layer formats the screen so the web page appears properly no matter what device is being used to view the web site.
A student has two web browser windows open in order to access two web sites. The transport layer ensures the correct web page is delivered to the correct browser window.*
A student is playing a short web-based movie with sound. The movie and sound are encoded within the transport layer header.

6
Which transport layer feature is used to guarantee session establishment?
UDP ACK flag
TCP 3-way handshake*
UDP sequence number
TCP port number

7
What is the complete range of TCP and UDP well-known ports?
0 to 255
256 – 1023
0 to 1023*
1024 – 49151

8
Which two TCP header fields are used to confirm receipt of data?
checksum
acknowledgment number*
FIN flag
sequence number*
SYN flag

9
​What is a beneficial feature of the UDP transport protocol?
acknowledgment of received data
tracking of data segments using sequence numbers
fewer delays in transmission*
the ability to retransmit lost data

10
Which two flags in the TCP header are used in a TCP three-way handshake to establish connectivity between two network devices? (Choose two.)
RST
FIN
SYN*
ACK*
URG
PSH

11
What happens if the first packet of a TFTP transfer is lost?
The TFTP application will retry the request if a reply is not received.*
The next-hop router or the default gateway will provide a reply with an error code.
The client will wait indefinitely for the reply.
The transport layer will retry the query if a reply is not received.

12
Compared to UDP, what factor causes additional network overhead for TCP communication?
the identification of applications based on destination port numbers
the checksum error detection
the encapsulation into IP packets
network traffic that is caused by retransmissions*

13. Match the characteristic to the protocol category. (Not all options are used.)



TCP  ->  window size
TCP  -> 3-way handshake
UDP -> connectionless
UDP -> best for VoIP
Both UDP and TCP -> checksum
Both UDP and TCP -> port number

14
Which factor determines TCP window size?
the amount of data the destination can process at one time*
the number of services included in the TCP segment
the amount of data the source is capable of sending at one time
the amount of data to be transmitted

15. Match each application to its connectionless or connection-oriented protocol.



TCP  -> HTTP
TCP  -> FTP
TCP  -> TELNET
UDP  -> TFTP
UDP  -> DHCP

16
During a TCP session, a destination device sends an acknowledgment number to the source device. What does the acknowledgment number represent?
the last sequence number that was sent by the source
one number more than the sequence number
the next byte that the destination expects to receive*
the total number of bytes that have been received

17
What is a socket?
the combination of the source and destination sequence numbers and port numbers
the combination of the source and destination sequence and acknowledgment numbers
the combination of a source IP address and port number or a destination IP address and port number*
the combination of the source and destination IP address and source and destination Ethernet address

18
Fill in the blank.
During a TCP session, the    “SYN”   field is used by the client to request communication with the server.

19
Fill in the blank using a number.

A total of   __4__    messages are exchanged during the TCP session termination process between the client and the server.

20
A host device sends a data packet to a web server via the HTTP protocol. What is used by the transport layer to pass the data stream to the proper application on the server?
source port number
destination port number*
sequence number
acknowledgment

21
What does a client do when it has UDP datagrams to send?
It just sends the datagrams.*
It queries the server to see if it is ready to receive data.
It sends a simplified three-way handshake to the server.
It sends to the server a segment with the SYN flag set to synchronize the conversation.

22
What does a client application select for a TCP or UDP source port number?
a predefined value in the dynamic port range
a predefined value in the range of the registered ports
a predefined value in the well-known port range
a random value in the dynamic port range
a random value in the range of the registered ports*
a random value in the well-known port range

UPDATE WITH QUESTIONS CCNA v5.1

23. How many bits are in an IPv4 address?

32*
64
128
256

24. Which two parts are components of an IPv4 address? (Choose two.)

subnet portion
network portion*
logical portion
host portion*
physical portion
broadcast portion

25. What does the IP address 172.17.4.250/24 represent?

network address
multicast address
host address*
broadcast address

26. What is the purpose of the subnet mask in conjunction with an IP address?

to uniquely identify a host on a network
to identify whether the address is public or private
to determine the subnet to which the host belongs*
to mask the IP address to outsiders

27. What subnet mask is represented by the slash notation /20?

255.255.255.248
255.255.224.0
255.255.240.0*
255.255.255.0
255.255.255.192

28. A message is sent to all hosts on a remote network. Which type of message is it?

limited broadcast
multicast
directed broadcast*
unicast

29. What are three characteristics of multicast transmission? (Choose three.)

The source address of a multicast transmission is in the range of 224.0.0.0 to 224.0.0.255.
A single packet can be sent to a group of hosts.*
Multicast transmission can be used by routers to exchange routing information.*
The range of 224.0.0.0 to 224.0.0.255 is reserved to reach multicast groups on a local network.*
Computers use multicast transmission to request IPv4 addresses.
Multicast messages map lower layer addresses to upper layer addresses.

30. Which three IP addresses are private ? (Choose three.)

10.1.1.1*
172.32.5.2
192.167.10.10
172.16.4.4*
192.168.5.5*
224.6.6.6

31. Which two IPv4 to IPv6 transition techniques manage the interconnection of IPv6 domains? (Choose two.)

trunking
dual stack*
encapsulation
tunneling*
multiplexing

32. Which of these addresses is the shortest abbreviation for the IP address:

3FFE : 1044 : 0000 : 0000 : 00AB : 0000 : 0000 : 0057?

3FFE : 1044 :: AB :: 57
3FFE : 1044 :: 00AB :: 0057
3FFE : 1044 : 0 : 0 : AB :: 57*
3FFE : 1044 : 0 : 0 : 00AB :: 0057
3FFE : 1044 : 0000 : 0000 : 00AB :: 57
3FFE : 1044 : 0000 : 0000 : 00AB :: 0057

33. What type of address is automatically assigned to an interface when IPv6 is enabled on that interface?

global unicast
link-local*
loopback
unique local

34. What are two types of IPv6 unicast addresses? (Choose two.)

multicast
loopback*
link-local*
anycast
broadcast

35. What are three parts of an IPv6 global unicast address? (Choose three.)

an interface ID that is used to identify the local network for a particular host
a global routing prefix that is used to identify the network portion of the address that has been provided by an ISP*
a subnet ID that is used to identify networks inside of the local enterprise site*
a global routing prefix that is used to identify the portion of the network address provided by a local administrator
an interface ID that is used to identify the local host on the network*

36. An administrator wants to configure hosts to automatically assign IPv6 addresses to themselves by the use of Router Advertisement messages, but also to obtain the DNS server address from a DHCPv6 server. Which address assignment method should be configured?

SLAAC
stateless DHCPv6*
stateful DHCPv6
RA and EUI-64

37. Which protocol supports Stateless Address Autoconfiguration (SLAAC) for dynamic assignment of IPv6 addresses to a host?

ARPv6
DHCPv6
ICMPv6*
UDP

38. Which two things can be determined by using the ping command? (Choose two.)

the number of routers between the source and destination device
the IP address of the router nearest the destination device
the average time it takes a packet to reach the destination and for the response to return to the source*
the destination device is reachable through the network*
the average time it takes each router in the path between source and destination to respond
39. What is indicated by a successful ping to the ::1 IPv6 address?

The host is cabled properly.
The default gateway address is correctly configured.
All hosts on the local link are available.
The link-local address is correctly configured.
IP is properly installed on the host.*
39. A user is executing a tracert to a remote device. At what point would a router, which is in the path to the destination device, stop forwarding the packet?

when the router receives an ICMP Time Exceeded message
when the RTT value reaches zero
when the host responds with an ICMP Echo Reply message
when the value in the TTL field reaches zero*
when the values of both the Echo Request and Echo Reply messages reach zero
40. What field content is used by ICMPv6 to determine that a packet has expired?

TTL field
CRC field
Hop Limit field*
Time Exceeded field
41. Fill in the blank.
The decimal equivalent of the binary number 10010101 is __149__ .
42. Fill in the blank.
The binary equivalent of the decimal number 232 is __11101000__
43. Fill in the blank.
What is the decimal equivalent of the hex number 0x3F? __63__
44. Match each description with an appropriate IP address. (Not all options are used.)



169.254.1.5 -> a link-local address
192.0.2.123 -> a TEST-NET address
240.2.6.255 -> an experimental address
172.19.20.5 -> a private address
127.0.0.1 -> a loopback address

45. What is the purpose of ICMP messages?

to inform routers about network topology changes
to ensure the delivery of an IP packet
to monitor the process of a domain name to IP address resolution
to provide feedback of IP packet transmissions*