Sunday, August 31, 2008

CCNA 4.0 module 4 (OSI transport layer)

Options ** are Correct Answer
1. Based on the transport layer header shown in the diagram, which of the following statements describe the established session? (Choose two.)
This is a UDP header.
**This contains a Telnet request.
This contains a TFTP data transfer.
The return packet from this remote host will have an Acknowledgement Number of 43693.
**This is a TCP header.

2. With TCP/IP data encapsulation, which range of port numbers identifies all well-known applications?
0 to 255
256 to 1022
**0 to 1023
1024 to 2047
49153 to 65535

3. Why are port numbers included in the TCP header of a segment?
to indicate the correct router interface that should be used to forward a segment
to identify which switch ports should receive or forward the segment
to determine which Layer 3 protocol should be used to encapsulate the data
**to enable a receiving host to forward the data to the appropriate application
to allow the receiving host to assemble the packet in the proper order

4. Which OSI model layer is responsible for regulating the flow of information from source to destination, reliably and accurately?
application
presentation
session
**transport
network

5. Refer to the exhibit. Host A is using FTP to download a large file from Server 1. During the download process, Server 1 does not receive an acknowledgment from Host A for several bytes of transferred data. What action will Server 1 take as a result?
create a Layer 1 jam signal
**reach a timeout and resend the data that needs to be acknowledged
send a RESET bit to the host
change the window size in the Layer 4 header

6. Why is flow control used for TCP data transfer?
to synchronize equipment speed for sent data
to synchronize and order sequence numbers so data is sent in complete numerical order
**to prevent the receiver from being overwhelmed by incoming data
to synchronize window size on the server
to simplify data transfer to multiple hosts

7. Which two options represent Layer 4 addressing? (Choose two.)
identifies the destination network
identifies source and destination hosts
**identifies the communicating applications
**identifies multiple conversations between the hosts
identifies the devices communicating over the local media

8. Refer to the exhibit. In line 7 of this Wireshark capture, what TCP operation is being performed?
**session establishment
segment retransmit
data transfer
session disconnect
Bottom of Form

9. Refer to the exhibit. What two pieces of information can be determined from the output that is shown? (Choose two.)
The local host is using well-known port numbers to identify the source ports.
**A termination request has been sent to 192.135.250.10.
**Communication with 64.100.173.42 is using HTTP Secure.
The local computer is accepting HTTP requests.
192.168.1.101:1042 is performing the three-way handshake with 128.107.229.50:80.

10. What is dynamically selected by the source host when forwarding data?
destination logical address
source physical address
default gateway address
**source port

11. What are two features of the User Datagram Protocol (UDP)? (Choose two.)
flow control
**low overhead
**connectionless
connection-oriented
sequence and acknowledgements

12. What mechanism is used by TCP to provide flow control as segments travel from source to destination?
sequence numbers
session establishment
**window size
acknowledgments

13. Which transport layer protocol provides low overhead and would be used for applications which do not require reliable data delivery?
TCP
IP
**UDP
HTTP
DNS

14. Which information is found in both the TCP and UDP header information?
sequencing
flow control
acknowledgments
**source and destination

15. Which three features allow TCP to reliably and accurately track the transmission of data from source to destination?
encapsulation
**flow control
connectionless services
**session establishment
**numbering and sequencing
best effort delivery

16. During a TCP communication session, if the packets arrive to the destination out of order, what will happen to the original message?
The packets will not be delivered.
The packets will be retransmitted from the source.
**The packets will be delivered and reassembled at the destination.
The packets will be delivered and not reassembled at the destination.

17. Which is an important characteristic of UDP?
acknowledgement of data delivery
**minimal delays in data delivery
high reliability of data delivery
same order data delivery

18. After a web browser makes a request to a web server that is listening to the standard port, what will be the source port number in the TCP header of the response from the server?
13
53
**80
1024
1728

19. Which event occurs during the transport layer three-way handshake?
The two applications exchange data.
**TCP initializes the sequence numbers for the sessions.
UDP establishes the maximum number of bytes to be sent.
The server acknowledges the bytes of data received from the client.

20. Refer to the exhibit. Host1 is in the process of setting up a TCP session with Host2. Host1 has sent a SYN message to begin session establishment. What happens next?
Host1 sends a segment with the ACK flag = 0, SYN flag = 0 to Host2.
Host1 sends a segment with the ACK flag = 1, SYN flag = 0 to Host2.
Host1 sends a segment with the ACK flag = 1, SYN flag = 1 to Host2.
Host2 sends a segment with the ACK flag = 0, SYN flag = 1 to Host1.
Host2 sends a segment with the ACK flag = 1, SYN flag = 0 to Host1.
**Host2 sends a segment with the ACK flag = 1, SYN flag = 1 to Host1

21. Refer to the exhibit. What two pieces of information can be determined from the output that is shown? (Choose two.)
**The local host is using three client sessions.
**The local host is using web sessions to a remote server.
The local host is listening for TCP connections using public addresses.
The local host is using well-known port numbers to identify the source ports.
The local host is performing the three-way handshake with 192.168.101:1037.

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CCNA 4.0 module 3 (Application layer functionality and Protocols)

Options ** are Correct Answer
1. What application layer protocol is commonly used to support for file transfers between a client and a server?
HTML
**HTTP
FTP
Telnet

2. What are two forms of application layer software? (Choose two.)
**applications
dialogs
requests
**services
syntax

3. A network administrator is designing a network for a new branch office of twenty-five users. What are the advantages of using a client-server model? (Choose two.)
**centralized administration
does not require specialized software
**security is easier to enforce
lower cost implementation
provides a single point of failure

4. What is the purpose of resource records in DNS?
temporarily holds resolved entries
**used by the server to resolve names
sent by the client to during a query
passes authentication information between the server and client

5. What is the automated service that matches resource names with the required IP address?HTTP
SSH
FQDN
**DNS
Telnet
SMTP

6. What three protocols operate at the Application layer of the OSI model? (Choose three.)
ARP
**DNS
PPP
**SMTP
**POP
ICMP

7. What are three properties of peer-to-peer applications? (Choose three.)
**acts as both a client and server within the same communication.
requires centralized account administration.
**hybrid mode includes a centralized directory of files.
**can be used in client-server networks.
requires a direct physical connection between devices.
centralized authentication is required.

8. Which application layer protocols correctly match a corresponding function? (Choose two.)
DNS dynamically allocates IP addresses to hosts
**HTTP transfers data from a web server to a client
POP delivers email from the client to the server email server
SMTP supports file sharing
**Telnet provides a virtual connection for remote access

9. Which email components are used to forward mail between servers? (Choose two.)
MDA
IMAP
**MTA
POP
**SMTP
MUA

10. As compared to SSH, what is the primary disadvantage of telnet?
not widely available
**does not support encryption
consumes more network bandwidth
does not support authentication

11. Which statements are correct concerning the role of the MTA in handling email? (Choose three.)
routes email to the MDA on other servers
**receives email from the client's MUA
receives email via the POP3 protocol
**passes email to the MDA for final delivery
**uses SMTP to route email between servers
delivers email to clients via the POP3 protocol

12. Which two protocols are used to control the transfer of web resources from a web server to a client browser? (Choose two.)
ASP
FTP
HTML
**HTTP
**HTTPS
IP

13. A small home network has been installed to interconnect three computers together for gaming and file sharing. What two properties represent this network type? (Choose two.)
User accounts are centralized.
**Security is difficult to enforce.
Specialized operating system software is required.
File permissions are controlled by a single computer.
**A computer that responds to a file sharing request is functioning as a server.

14. Which layer of the OSI model supplies services that allow user to interface with the network?physical
session
network
presentation
**application
transport

15. Refer to the exhibit. What is the destination port for the communication that is represented on line 5?
**80
1261
15533
3912
65520

16. What are two characteristics of peer-to-peer networks? (Choose two.)
scalable
one way data flow
**decentralized resources
centralized user accounts
**resource sharing without a dedicated server

17. What application layer protocol describes the services that are used for file sharing in Microsoft networks?
DHCP
DNS
**SMB
SMTP
Telnet

18. What are two characteristics of clients in data networks? (Choose two.)
use daemons
**initiate data exchanges
are repositories of data
**may upload data to servers
listen for requests from servers

19. What is the role of the OSI application layer?
provides segmentation of data
provides encryption and conversion of data
**provides the interface between the applications on either end of the network
provides control of all the data flowing between the source and destination devices

20. How does the application layer on a server usually process multiple client request for services?
ceases all connections to the service
denies multiple connections to a single daemon
suspends the current connection to allow the new connection
**uses support from lower layer functions to distinguish between connections to the service

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CCNA 4.0 module 2 (Communicating over the network)

Options ** are Correct Answer
1. Which statements correctly identify the role of intermediary devices in the network? (Choose three.)
**determine pathways for data.
initiate data communications.
**retime and retransmit data signals.
originate the flow of data .
**manage data flows.
final termination point for data flow.

2. Select the statements that are correct concerning network protocols. (Choose three.)
**define the structure of layer specific PDU's.
dictate how to accomplish layer functions.
**outline the functions necessary for communications between layers.
limit hardware compatibility.
**require layer dependent encapsulations.
eliminate standardization among vendors.

3. What are the key functions of encapsulation? (Choose three.)
allows modification of the original data before transmission.
**identifies pieces of data as part of the same communication.
enables consistent network paths for communication.
**ensures that data pieces can be directed to the correct receiving end device.
**enables the reassembly of complete messages.
tracks delay between end devices.

4. Which two layers of the OSI model have the same functions as the TCP/IP model Network Access Layer? (Choose two.)
Network.
Transport.
**Physical.
**Data Link.
Session.

5. What is a PDU?
corruption of a frame during transmission.
data reassembled at the destination.
retransmitted packets due to lost communication.
**a layer specific encapsulation.

6. Which characteristic correctly refers to end devices in a network?
manage data flows.
**originate data flow.
retime and retransmit data signals.
determine pathways for data.

7. Refer to the exhibit. "Cell A" at IP address 10.0.0.34 has established an IP session with "IP Phone 1" at IP address 172.16.1.103. Based upon the graphic, which device type best describes the function of wireless device "Cell A?"
the destination device
**an end device
an intermediate device
a media device

8. Refer to the exhibit. Which three labels correctly identify the network types for the network segments that are shown? (Choose three.)
Network A -- WAN
**Network B -- WAN
**Network C -- LAN
Network B -- MAN
Network C -- WAN
**Network A -- LAN

9. Which three statements best describe a Local Area Network (LAN)? (Choose three.)
**A LAN is usually in a single geographical area.
**The network is administered by a single organization.
The connection between segments in the LAN is usually through a leased connection.
The security and access control of the network are controlled by a service provider.
**A LAN provides network services and access to applications for users within a common organization.
Each end of the network is generally connected to a Telecommunication Service Provider (TSP).

10. Refer to the exhibit. Which networking term describes the data interleaving process represented in the graphic?
piping
PDU
streaming
**multiplexing
encapsulation

11. What is the primary purpose of Layer 4 port assignment?
to identify devices on the local media
to identify the hops between source and destination
to identify to the intermediary devices the best path through the network
to identify the source and destination end devices that are communicating
**to identify the processes or services that are communicating within the end devices

12. What device is considered an intermediary device?
file server
IP phone
laptop
printer
**switch

13. Refer to the exhibit. Which term correctly identifies the device type that is included in the area B?
source
end
transfer
**intermediary

14. Refer to the exhibit. What type of network is shown?
WAN
MAN
**LAN
WLAN

15. Which layer encapsulates the segment into packets?
physical
data link
**network
transport

16. What can be identified by examining the network layer header?
the destination device on the local media
**the destination host address
the bits that will be transferred over the media
the source application or process creating the data

17. Refer to the exhibit. Which set of devices contains only end devices?
A, C, D
B, E, G, H
C, D, G, H, I, J
D, E, F, H, I, J
**E, F, H, I, J

18. During the encapsulation process, what occurs at the data link layer?
No address is added.
The logical address is added.
**The physical address is added.
The process port number is added.

19. What is the purpose of the TCP/IP Network Access layer?
path determination and packet switching
data representation, encoding, and control
reliability, flow control, and error detection
**detailing the components that make up the physical link and how to access it
the division of segments into packets

20. What is the proper order of the layers of the OSI model from the highest layer to the lowest layer?
physical, network, application, data link, presentation, session, transport
application, physical, session, transport, network, data link, presentation
application, presentation, physical, session, data link, transport, network
**application, presentation, session, transport, network, data link, physical
presentation, data link, session, transport, network, physical, application

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