CNA 101 | Ch. 10 Application Layer

Trivial File Transfer Protocol (TFTP)

Which well-known application layer protocol is simple, connectionless, and uses best-effort delivery?

DHCP offer (DHCPOFFER)

A DHCP server replies with a ___________ message, which offers a lease to the client.

peer-to-peer application (P2P application)

A ___________allows a device to act as both a client and a server within the same communication. This requires that each end device provide a user interface and run a background service.

IPv4 address to be assigned, subnet mask to be assigned, IPv4 address of the DNS server, and the IPv4 address of the default gateway.

A response message from a DHCP server contains four pieces of information, what are these pieces?

.com

What domain would a business or industry use?

.org

What domain would a non-profit use?

.au

What domain would be used in Australia?

.co

What domain would be used in Columbia?

Header Question Answer Authority Additional

What five pieces make up the DNS message format?

client-server network

An architecture that allows network clients to request services directly from network servers

swarm | BitTorrent

Clients ask for pieces from multiple users at the same time, known as a __________. This technology is called ___________.

gtk-gnutella, WireShare, Shareaza, and Bearshare.

Give four examples of available Gnutella client applications.

torrent file

Clients use a small file called a ________ to locate other users who have pieces that they need so that they can connect directly to them.

nslookup

Computer operating systems have a utility called __________that allows the user to manually query the name servers to resolve a given host name.

session layer

Functions at the _____________ create and maintain dialogs between source and destination applications.

GET, POST, and PUT

HTTP uses three common message types. What are they?

Secure Socket Layer (SSL)

HTTPS uses the same client request-server response process as HTTP, but the data stream is encrypted with ________________ before being transported across the network.

DHCP request (DHCPREQUEST)

If a client device receives multiple responses from DHCP devices, it must choose between them, and sends a _____________ message that identifies the explicit server and lease offer that the client is accepting.

Client-Server

In a ___________ model, the device requesting the information is called a client and the device responding to the request is called a server.

Domain names

In data networks, devices are labeled with numeric IP addresses to send and receive data over networks. _________ were created to convert the numeric address into a simple, recognizable name.

peer-to-peer (P2P)

In the __________ networking model, the data is accessed from a peer device without the use of a dedicated server.

Gnutella protocol

Some P2P applications are based on the ____________, where each user shares whole files with other users

message

The DNS protocol communications use a single format called a ________. This format is used for all types of client queries and server responses, error messages, and the transfer of resource record information between servers.

MX

The DNS server stores different types of resource records used to resolve names. Which record type is a mail exchange record?

NS

The DNS server stores different types of resource records used to resolve names. Which record type is an authoritative name server?

A

The DNS server stores different types of resource records used to resolve names. Which record type is an end device IPv4 address?

AAAA (quad-a)

The DNS server stores different types of resource records used to resolve names. Which record type is an end device IPv6 address?

GET

The HTTP message type used by the client to request data from the web server is the _____ message.​

ipconfig /displaydns

The _______________ command displays all of the cached DNS entries.

Dynamic Host Configuration Protocol (DHCP)

The __________________ for IPv4 service automates the assignment of IPv4 addresses, subnet masks, gateways, and other IPv4 networking parameters.

SMTP IMAP

The application layer process that sends mail uses __________. A client retrieves email, however, using one of the two application layer protocols: POP or _______.

True.

True or False. An email client does not communicate directly with another email client when sending email.

False. FTP requires twp connections between a file and server. One for command and replies, the other for the transfer.

True or False. FTP requires only a single connection between the client and server.

True

True or False. On larger networks, or where the user population changes frequently, DHCP is preferred for address assignment.

True

True or False. When a DNS server receives a request for a name translation that is not within its DNS zone, the DNS server forwards the request to another DNS server within the proper zone for translation.

True

True or False. With FTP the data transfer can happen in either direction. The client can download (pull) data from the server, or the client can upload (push) data to the server.

False. This is only true for IMAP.

True or False. With both POP and IMAP original messages are kept on the server until manually deleted. Users view copies of the messages in their email client software.

Uniform Resource Identifier (URIs)

URLs and _______________ are the names most people associate with web addresses.

POST

What HTTP message uploads data files to the web server such as form data?

PUT

What HTTP message uploads resources or content to the web server such as an image?

File Transfer Protocol (FTP) (20/21), Simple Mail Transfer Protocol (SMTP) (25) Domain Name System (DNS) (53), Trivial File Transfer Protocol (TFTP) (69), Hyper Text Transfer Protocol (HTTP) (80), Post Office Protocol (POPv3) (110), and Internet Message Access Protocol (IMAP) (143).

What are the seven most widely known application layer protocols, and their port numbers, according to the chapter material?

Graphics Interchange Format (GIF), Joint Photographic Experts Group (JPEG), and Portable Network Graphics (PNG) format.

What are the three most well-known graphic image formats that are used on networks according to the chapter material?

Formatting at source for destination Compressing so destination can decompress Encryption and Decryption

What are the three primary functions of the Application Layer?

A client initiates the request with a server The server responds with code to the client A browser interprets it and shows a webpage for the client

What are the three steps for the HTTP protocol?

QuickTime Motion Picture Experts Group (MPEG)

What are the two most well-known standards for video according to the chapter material?

A. A workstation initiates a DNS request when the user types www.cisco.com in the address bar of a web browser.

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

DHCPv6 does not provide a default gateway address.

What is the one major difference between DHCP and DHCPv6?

uniform resource locator (URL)

When a web address or ____________ is typed into a web browser, the web browser establishes a connection to the web service running on the server using the HTTP protocol.

DHCP acknowledgment (DHCPACK) DHCP negative acknowledgment (DHCPNAK)

When an IPv4 address requested by the client is confirmed as available, the server returns a __________ message that informs the client that the lease has been finalized. If the offer is no longer valid, then the selected server responds with a ________ message.

DHCP discover (DHCPDISCOVER)

When an IPv4, DHCP-configured device boots up or connects to the network, the client broadcasts a _____________ message to identify any available DHCP servers on the network.

Dynamic Host Configuration Protocol (DHCP)

Which application layer protocol dynamically assigned IP addresses to client stations at start-up?

Bootstrap Protocol (BOOTP)

Which application layer protocol enables a disk-less workstation to discover its own IP address?

Simple Mail Transfer Protocol (SMTP)

Which application layer protocol enables clients and servers to send email to servers?

Internet Message Access Protocol (IMAP)

Which application layer protocol enables clients to access email stored on a mail server?

Post Office Protocol (POPv3)

Which application layer protocol enables clients to retrieve email from a mail server?

Server Message Block (SMB)

Which application layer protocol is used to provide file-sharing and print services to Microsoft applications?

Hypertext Transfer Protocol (HTTP)

Which application layer protocol sets rules for exchanging text, graphic images, sound, video and other multimedia files on the World Wide Web?

File Transfer Protocol (FTP)

Which application layer protocol sets rules that enable a user on one host to access and send files to and from another host over a network?

Domain Name System (DNS)

Which application layer protocol translates domain names, such as cisco.com, into IP addresses?

Hypertext Transfer Protocol Secure (HTTPS)

Which application layer protocol uses encryption to strengthen HTTP communications?

application, presentation, and session

Which layers of the OSI model define functions of the single TCP/IP application layer?

B. A program that is running on an FTP server

Which phrase describes an FTP daemon? A. A diagnostic FTP program B. A program that is running on an FTP server C. A program that is running on an FTP client D. An application that is used to request data from an FTP server

D. The message comes from a client seeking an IP address. E. The destination IP address is 255.255.255.255. F. All hosts receive the message, but only a DHCP server replies.

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

21

With FTP a client establishes the first connection to the server for control traffic using TCP port __, consisting of client commands and server replies.

20

With FTP a client establishes the second connection to the server for the actual data transfer using TCP port __.

eDonkey, G2, BitTorrent, and Bitcoin

With P2P applications, each computer in the network running the application can act as a client or a server for the other computers in the network running the application. Four common P2P network applications are?

Services

_________ are background programs that provide the connection between the application layer and the lower layers of the networking model.

Applications

_________ are computer programs with which the user interacts and which initiate the data transfer process at the user's request.

Protocols

_________ provide a structure of agreed-upon rules and processes that ensure services running on one particular device can send and receive data from a range of different network devices.

POP

______is used by an application to retrieve mail from a mail server. With this, mail is downloaded from the server to the client and then deleted on the server.