CCNA1 v7 - Modules 14-15

What is the complete range of TCP and UDP well-known ports?

0 to 1023

What is the order of each step in the termination process for a TCP session?

1. Client sends a server a segment with the FIN flag set 2. The server acknowledges the client by sending a segment with the ACK flag set 3. The server sends a FIN to the client to terminate the server to client session. 4. The client acknowledges the termination by sending a segment with the ACK flag set. *Client-FIN, Server-ACK, Server-FIN, Client-ACK*

What characteristics are associated with UDP sessions?

1. Destination devices will not acknowledge received data 2. Headers use very little overhead and cause minimal delay.​

What are three responsibilities of the transport layer?

1. Meeting the reliability requirements of applications, if any 2. Multiplexing multiple communication streams from many users or applications on the same network 3. Identifying the applications and services on the client and server that should handle transmitted data

What are some roles of the transport layer in data communication on a network?

1. Tracking the individual communication streams between applications on the source and destination hosts 2. Segmenting data at the source and reassembling the data at the destination 3. Identifying the proper application for each communication stream through the use of port numbers

In what two situations would UDP be better than TCP as the preferred transport protocol?

1. When a faster delivery mechanism is needed 2. When applications do not need to guarantee delivery of the data

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?

10 segments

A client creates a packet to send to a server. The client is requesting POP3 service. What number will be used as the destination port number in the sending packet?

110

A client creates a packet to send to a server. The client is requesting SNMP service. What number will be used as the destination port number in the sending packet?

161

A client creates a packet to send to a server. The client is requesting FTP service. What number will be used as the destination port number in the sending packet?

21

A client creates a packet to send to a server. The client is requesting SSH service. What number will be used as the destination port number in the sending packet?

22

A client creates a packet to send to a server. The client is requesting telnet service. What number will be used as the destination port number in the sending packet?

23

A client creates a packet to send to a server. The client is requesting SMTP service. What number will be used as the destination port number in the sending packet?

25

A PC that is communicating with a web server has a TCP window size of 6,000 bytes when sending data and a packet size of 1,500 bytes. Which byte of information will the web server acknowledge after it has received two packets of data from the PC?

3001

A client creates a packet to send to a server. The client is requesting HTTPS service. What number will be used as the destination port number in the sending packet?

443

A PC that is communicating with a web server has a TCP window size of 6,000 bytes when sending data and a packet size of 1,500 bytes. Which byte of information will the web server acknowledge after it has received three packets of data from the PC?

4501

A client creates a packet to send to a server. The client is requesting TFTP service. What number will be used as the destination port number in the sending packet?

69

A client creates a packet to send to a server. The client is requesting HTTP service. What number will be used as the destination port number in the sending packet?

80

Which three statements characterize UDP? A) UDP provides basic connectionless transport layer functions. B) UDP provides connection-oriented, fast transport of data at Layer 3. C) UDP relies on application layer protocols for error detection. D) UDP is a low overhead protocol that does not provide sequencing or flow control mechanisms. E) UDP relies on IP for error detection and recovery. F) UDP provides sophisticated flow control mechanisms.

A, C, and D

Which flag in the TCP header is used in response to a received FIN in order to terminate connectivity between two network devices?

ACK

Which OSI layer provides the interface between the applications used to communicate and the underlying network over which messages are transmitted?

Application Layer

Which layer in the TCP/IP model is used for formatting, compressing, and encrypting data?

Application Layer

Which three statements describe a DHCP Discover message? A) The source MAC address is 48 ones (FF-FF-FF-FF-FF-FF). B) The destination IP address is 255.255.255.255. C) The message comes from a server offering an IP address. D) Message comes from a client seeking an IP address. E) All hosts receive the message, but only a DHCP server replies. F) Only the DHCP server receives the message.

B, D, and E

Why does HTTP use TCP as the transport layer protocol?

Because HTTP requires reliable delivery

What do the client/server and peer-to-peer network models have in common?

Both models support devices in server and client roles.

Which two types of applications are best suited for UDP? A) applications that need data flow control B) applications that require reliable delivery C) applications that handle reliability themselves D) applications that need the reordering of segments E) applications that can tolerate some data loss, but require little or no delay

C and E

Which networking model is being used when an author uploads one chapter document to a file server of a book publisher?

Client/server

What is true about the Server Message Block protocol?

Clients establish a long term connection to servers.

Which field in the TCP header indicates the status of the three-way handshake process?

Control bits

What is an example of network communication that uses the client-server model? A) A user uses eMule to download a file that is shared by a friend after the file location is determined. B) A workstation initiates an ARP to find the MAC address of a receiving host. C) A user prints a document by using a printer that is attached to a workstation of a coworker. D) A workstation initiates a DNS request when the user types www.cisco.com in the address bar of a web browser.

D

Which three protocols operate at the application layer of the TCP/IP model? A) ARP B) TCP C) UDP D) FTP E) POP3 F) DHCP

D, E, and F

Which protocol or service uses UDP for a client-to-server communication and TCP for server-to-server communication?

DNS (Domain Name System)

What important information is added to the TCP/IP transport layer header to ensure communication and connectivity with a remote network device?

Destination and source port numbers

A manufacturing company subscribes to certain hosted services from its ISP. The services that are required include hosted world wide web, file transfer, and e-mail. Which protocols represent these three key applications?

FTP (File transfers), HTTP (Web pages), SMTP (E-mail)

What is a common protocol that is used with peer-to-peer applications such as WireShare, Bearshare, and Shareaza?

Gnutella

Which application layer protocol uses message types such as GET, PUT, and POST?

HTTP

Which protocol is used by a client to communicate securely with a web server?

HTTPS

How are port numbers used in the TCP/IP encapsulation process?

If multiple conversations occur that are using the same service, the source port number is used to track the separate conversations.

What does a client do when it has UDP datagrams to send?

It just sends the datagrams.

Which applications or services allow hosts to act as client and server at the same time?

P2P applications

In what networking model would eDonkey, eMule, BitTorrent, Bitcoin, and LionShare be used?

Peer-to-peer

What kind of port must be requested from IANA in order to be used with a specific application?

Registered port

What is a key characteristic of the peer-to-peer networking model?

Resource sharing without a dedicated serve

What is an advantage of SMB over FTP?​

SMB clients can establish a long-term connection to the server.​

Which two protocols may devices use in the application process that sends email?

SMTP and DNS

Which three application layer protocols use TCP?

SMTP, FTP, and HTTP

What information is used by TCP to reassemble and reorder received segments?

Sequence numbers

The application layer of the TCP/IP model performs the functions of what three layers of the OSI model?

Session, Presentation, and Application

What are the fields are used in a UDP segment header?

Source Port, Destination Port, Length, and Checksum fields.

Which transport layer feature is used to guarantee session establishment?

TCP 3-way handshake

Which factor determines TCP window size?

The amount of data the destination can process at one time

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.

What is a socket?

The combination of a source IP address and port number or a destination IP address and port number

What type of information is contained in a DNS MX record?

The domain name mapped to mail exchange servers

What is the function of the HTTP GET message?

To request an HTML page from a web server

Which two fields are included in the TCP header but not in the UDP header?

Window and sequence number