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Sabtu, 10 Februari 2018

quis chapter 10 CCNA

1. What is an advantage of SMB over FTP??
  Only with SMB can data transfers occur in both directions.
  Only SMB establishes two simultaneous connections with the client, making the data transfer faster.
  SMB is more reliable than FTP because SMB uses TCP and FTP uses UDP.
  SMB clients can establish a long-term connection to the server. *
Refer to curriculum topic: 10.2.3
SMB and FTP are client/server protocols that are used for file transfer. SMB allows the connecting device to access resources as if they were on the local client device. SMB and FTP use the TCP protocol for connection establishment and they can transfer data in both directions. FTP requires two connections between the client and the server, one for commands and replies, the other for the actual file transfer.


2. What is true about a client-server network?
  The network includes a dedicated server. *
  Each device can function as a server and a client.
  Workstations access network resources using SAMBA or Gnutella.
  Each peer accesses an index server to get the location of a resource stored on another peer in what is considered a hybrid network system.
Refer to curriculum topic: 10.1.2
In a client-server network, a dedicated server responds to service requests from clients. The roles of client and server are not shared on each host in the network. In a peer-to-peer network, computers are connected via a network and can share resources. Each host can function as a server or a client based on the nature of the transaction and what resources are used or requested. A hybrid network is one in which a server supplies index information that enables a peer to locate resources on other peers. In this case the peers can still have the role of client or server depending on the nature of the network transaction.


3. True or False?

In FTP transactions, an FTP client uses the pull method to download files from an FTP server.
  true *
  false 
Refer to curriculum topic: 10.2.3
The File Transfer Protocol (FTP) is a commonly used application layer protocol. FTP allows for data transfers between a client and a server. During data transfers, the FTP client downloads (pulls) data from the server. The FTP client can also upload (push) data to the server.

 
4. Why is DHCP preferred for use on large networks?
  Large networks send more requests for domain to IP address resolution than do smaller networks.
  DHCP uses a reliable transport layer protocol. 
  It prevents sharing of files that are copyrighted. 
Correct!
  It is a more efficient way to manage IP addresses than static address assignment.
  Hosts on large networks require more IP addressing configuration settings than hosts on small networks.
Refer to curriculum topic: 10.2.2
Static IP address assignment requires personnel to configure each network host  with addresses manually. Large networks can change frequently and have many more hosts to configure than do small networks. DHCP provides a much more efficient means of configuring and managing IP addresses on large networks than does static address assignment.

 
5. What is a common protocol that is used with peer-to-peer applications such as WireShare, Bearshare, and Shareaza?
  Ethernet 
  Gnutella * 
  POP 
  SMTP 
Refer to curriculum topic: 10.1.2
The Gnutella protocol is used when one user shares an entire file with another user. A person would load a Gnutella-based application such as gtk-gnutella or WireShare and use that application to locate and access resources shared by others.

 
6. A user is attempting to access http://www.cisco.com/ without success. Which two configuration values must be set on the host to allow this access? (Choose two.)
  DNS server *
  source port number 
  HTTP server 
  default gateway * 
  source MAC address 
Refer to curriculum topic: 10.2.2
In order to use a URL such as http://www.cisco.com, the DNS protocol must be used in order to translate the URL into an IP address. Furthermore, the host device requesting this web page must have a default gateway configured in order to communicate with remote networks.

 
7. What type of information is contained in a DNS MX record?
  the FQDN of the alias used to identify a service 
  the IP address for an FQDN entry 
  the domain name mapped to mail exchange servers *
  the IP address of an authoritative name server 
Refer to curriculum topic: 10.2.2
MX, or mail exchange messages, are used to map a domain name to several mail exchange servers that all belong to the same domain.


8. Which TCP/IP model layer is closest to the end user?
  application *
  internet 
  network access 
  transport 
Refer to curriculum topic: 10.1.1
End users use applications to interact with and use the network. The application layer of the TCP/IP model is closest to the end user. Application layer protocols are used to communicate and exchange messages with other network devices and applications. The layers of the TCP/IP model are from top to bottom (memory aid - ATIN): application, transport, internet, network access

 
9. Which command is used to manually query a DNS server to resolve a specific host name?
  nslookup *
  ipconfig /displaydns
  tracert
  ping
Refer to curriculum topic: 10.2.2
The nslookup command was created to allow a user to manually query a DNS server to resolve a given host name. The ipconfig /displaydns command only displays previously resolved DNS entries. The tracert command was created to examine the path that packets take as they cross a network and can resolve a hostname by automatically querying a DNS server. The ping command was created to test reachability on a network and can resolve a hostname by automatically querying a DNS server.

 
10. A wired laser printer is attached to a home computer. That printer has been shared so that other computers on the home network can also use the printer. What networking model is in use?
  peer-to-peer (P2P) * 
  client-based 
  master-slave 
  point-to-point 
Refer to curriculum topic: 10.1.2
Peer-to-peer (P2P) networks have two or more network devices that can share resources such as printers or files without having a dedicated server.


11. Which three layers of the OSI model provide similar network services to those provided by the application layer of the TCP/IP model? (Choose three.)
  physical layer 
  session layer *
  transport layer 
  application layer * 
  presentation layer *
  data link layer 
Refer to curriculum topic: 10.1.1
The three upper layers of the OSI model, the session, presentation, and application layers, provide application services similar to those provided by the TCP/IP model application layer. Lower layers of the OSI model are more concerned with data flow.

 
12. On a home network, which device is most likely to provide dynamic IP addressing to clients on the home network?
  a home router *
  an ISP DHCP server 
  a DNS server 
Refer to curriculum topic: 10.2.2
On a home network, a home router usually serves as the DHCP server. The home router is responsible for dynamically assigning IP addresses to clients on the home network. ISPs also use DHCP, but it usually assigns an IP address to the Internet interface of the home router, not the clients on the home network. In businesses, it is common to have a file or other dedicated server provide DHCP services to the network. Finally, a DNS server is responsible for finding the IP address for a URL, not for providing dynamic addressing to network clients.

 
13. Which three protocols or standards are used at the application layer of the TCP/IP model? (Choose three.)
  TCP 
  HTTP * 
  MPEG *
  GIF *
  IP 
  UDP 
Refer to curriculum topic: 10.1.1
HTTP, MPEG, and GIF operate at the application layer of the TCP/IP model. TCP and UDP operate at the transport layer. IP operates at the internet layer.

 
14. Which protocol can be used to transfer messages from an email server to an email client?
  SMTP 
  POP3 *
  SNMP 
  HTTP 
Refer to curriculum topic: 10.2.1
SMTP is used to send mail from the client to the server but POP3 is used to download mail from the server to the client. HTTP and SNMP are protocols that are unrelated to email.

quis chapter 9 CCNA

1. Which transport layer feature is used to guarantee session establishment?
TCP 3-way handshake *
Refer to curriculum topic: 9.2.1
TCP uses the 3-way handshake. UDP does not use this feature. The 3-way handshake ensures there is connectivity between the source and destination devices before transmission occurs.

2. Which two services or protocols use the preferred UDP protocol for fast transmission and low overhead? (Choose two)
DNS *
VoIP *
Refer to curriculum topic: 9.2.4
Both DNS and VoIP use UDP to provide low overhead services within a network implementation.

3. What type of applications are best suited for using UDP?
  applications that are sensitive to delay *
Refer to curriculum topic: 9.2.3
UDP is not a connection-oriented protocol and does not provide retransmission, sequencing, or flow control mechanisms. It provides basic transport layer functions with  a much lower overhead than TCP. Lower overhead makes UDP suitable for applications which are sensitive to delay.

4. Which action is performed by a client when establishing communication with a server via the use of UDP at the transport layer?
The client randomly selects a source port number. *
Refer to curriculum topic: 9.2.3
Because a session does not have to be established for UDP, the client selects a random source port to begin a connection. The random port number selected is inserted into the source port field of the UDP header.

5. Network congestion has resulted in the source learning of the loss of TCP segments that were sent to the destination. What is one way that the TCP protocol addresses this?
The source decreases the amount of data that it transmits before it receives an acknowledgement from the destination. *
Refer to curriculum topic: 9.2.2
If the source determines that the TCP segments are either not being acknowledged or are not acknowledged in a timely manner, then it can reduce the number of bytes it sends before receiving an acknowledgment. This does not involve changing the window size in the segment header. The source does not decrease the window size that is sent in the segment header. The window size in the segment header is adjusted by the destination host when it is receiving data faster than it can process it, not when network congestion is encountered.

6. A client application needs to terminate a TCP communication session with a server. Place the termination process steps in the order that they will occur. (Not all options are used.)
step 1 - client sends FI
step 2 - server sends ACK
step 3 - server sends FIN
step 4 - client sends ACK
Other Incorrect Match Options:
client sends SYN
server sends SYN
Refer to curriculum topic: 9.2.1
In order to terminate a TCP session, the client sends to the server a segment with the FIN flag set. The server acknowledges the client by sending a segment with the ACK flag set. The server sends a FIN to the client to terminate the server to client session. The client acknowledges the termination by sending a segment with the ACK flag set.


7. What are three responsibilities of the transport layer? (Choose three.)
 Meeting the reliability requirements of applications, if any *
 Multiplexing multiple communication streams from many users 
  or applications on the same network *
  Identifying the applications and services on the client and server 
  that should handle transmitted data *
  Directing packets towards the destination network 
  Formatting data into a compatible form for receipt by the destination devices
  conducting error detection of the contents in frames 
Refer to curriculum topic: 9.1.1
The transport layer has several responsibilities. Some of the primary responsibilities include the following:

Tracking the individual communication streams between applications on the source and destination
Segmenting data at the source and reassembling the data at the destination
Identifying the proper application for each communication stream through the use of port numbers
Multiplexing the communications of multiple users or applications over a single network
Managing the reliability requirements of applications

8. What OSI layer is responsible for establishing a temporary communication session between two applications and ensuring that transmitted data can be reassembled in proper sequence?
  transport *
  network 
  data link 
  session 
Refer to curriculum topic: 9.1.1
The transport layer of the OSI model has several responsibilities. One of the primary responsibilities is to segment data into blocks that can be reassembled in proper sequence at the destination device.

9. What is the purpose of using a source port number in a TCP communication?
  to notify the remote device that the conversation is over 
  to assemble the segments that arrived out of order 
  to keep track of multiple conversations between devices * 
  to inquire for a nonreceived segment 
Refer to curriculum topic: 9.1.2
The source port number in a segment header is used to keep track of multiple conversations between devices. It is also used to keep an open entry for the response from the server. The incorrect options are more related to flow control and guaranteed delivery.


10.  What is an advantage of UDP over TCP?
  UDP communication requires less overhead. * 
  UDP communication is more reliable. 
  UDP reorders segments that are received out of order. 
  UDP acknowledges received data. 
Refer to curriculum topic: 9.1.2
TCP is a more reliable protocol and uses sequence numbers to realign packets that arrive out of order at the destination. Both UDP and TCP use port numbers to identify applications. UDP has less overhead than TCP because the UDP header has fewer bytes and UDP does not confirm the receipt of packets.

11.

Refer to the exhibit. What does the value of the window size specify?

  the amount of data that can be sent at one time 
  the total number of bits received during this TCP session 
  the amount of data that can be sent before an acknowledgment is required *
  a random number that is used in establishing a connection with the 3-way handshake
Refer to curriculum topic: 9.2.2
The window size specifies the amount of data that can be sent before an acknowledgment is received from the receiver. This value specifies the highest number of bytes, not the required number of bytes.

12. Which three fields are used in a UDP segment header? (Choose three.)
  Window Size 
  Length *
  Source Port * 
  Acknowledgment Number 
  Checksum *
  Sequence Number 
Refer to curriculum topic: 9.1.2
A UDP header consists of only the Source Port, Destination Port, Length, and Checksum fields. Sequence Number, Acknowledgment Number, and Window Size are TCP header fields.

13. Which number or set of numbers represents a socket?
  01-23-45-67-89-AB 
  21 
  192.168.1.1:80 *
  10.1.1.15 
Refer to curriculum topic: 9.1.2
A socket is defined by the combination of an IP address and a port number, and uniquely identifies a particular communication.

14. What is the purpose of the TCP sliding window?
  to inform a source to retransmit data from a specific point forward 
  to request that a source decrease the rate at which it transmits data *
  to end communication when data transmission is complete 
  to ensure that segments arrive in order at the destination 
Refer to curriculum topic: 9.2.2
The TCP sliding window allows a destination device to inform a source to slow down the rate of transmission. To do this, the destination device reduces the value contained in the window size field of the segment. It is acknowledgment numbers that are used to specify retransmission from a specific point forward. It is sequence numbers that are used to ensure segments arrive in order. Finally, it is a FIN control bit that is used to end a communication session.