Chapter 10 Application Layer
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) networks have two or more network devices that can share resources such as printers or files without having a dedicated server.
Which protocol can be used to transfer messages from an email server to an email client?
Post Office Protocol is used to download mail from the server to the client.
SMB and FTP are client/server TCP protocols that are used for file transfer. What is an advantage of SMB over FTP?
SMB clients can establish a long term connection to the server SMB allows the connecting device to access resources as if they were on the local client device. SMB uses the TCP protocol for connection establishment and they can transfer data in both directions.
When would it be more efficient to use SMB to transfer files instead of FTP?
when downloading large numbers of files from the same server
Which application layer protocol uses message types such as GET, PUT, and POST?
HTTP Trasfers files that make up the web pages of the World Wide Web The GET command is a client request for data from a web server. A PUT command uploads resources and content, such as images, to a web server. A POST command uploads data files to a web server.
What message type is used by an HTTP client to request data from a web server?
HTTP clients send GET messages to request data from web servers.
Which three protocols or standards are used at the application layer of the TCP/IP model?
HTTP, MPEG, and GIF operate at the application layer of the TCP/IP model.
What is a P2P network
A network where 2 or more computers are connected via a network and can share resources, without having a dedicated server,
Why is DHCP preferred for use on large networks?
DHCP provides a much more efficient means of configuring and managing IP addresses on large networks than does static address assignment.
DHCP enables clients on a network to do which of the following
Dynamically Obtain Internet Protocol Addresses
The HTTP message type used by the client to request data from the web server is the ____ message.
GET is one of the message types used by HTTP. A client (web browser) sends the GET message to the web server to request HTML pages.
Which protocol is used by a client to communicate securely with a web server?
HTTPS is a secure form of HTTP used to access web content hosted by a web server.
What is true about a client-server network?
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.
On a home network, which device is most likely to provide dynamic IP addressing to clients on the home network?
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.
The purpose of the Command: ipconfig /displaydns
Only displays previously resolved DNS entries.
Which definitions accurately describe the associated application layer protocol?
Telnet - Provides remote access to servers and networking devices DNS - Resolves Internet names to IP addresses HTTP- Trasfers files that make up the web pages of the WWW SMTP- Enables client to send email to servers, Enables servers to send email to other services FTP- Transfers files between systems
Which layer in the TCP/IP model is used for formatting, compressing, and encrypting data?
The application layer of the TCP/IP model is responsible for formatting, compressing, and encrypting data
Which three statements describe a DHCP Discover message?
The destination IP address is 255.255.255.255. The message comes from a client seeking an IP address. All hosts receive the message, but only a DHCP server replies.*
What are two characteristics of the application layer of the TCP/IP model?
is closest to the end user is used to create and maintain dialog between source and destination applications.
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?
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.
What command was used to resolve a given host name by querying the name servers?
A user can manually query the name servers to resolve a given host name using the nslookup command. Nslookup is both a command and a utility.
What is the acronym for the protocol that is used when securely communicating with a web server
HTTPS
What is an advantage for small organizations of adopting IMAP instead of POP?
IMAP and POP are protocols that are used to retrieve email messages. IMAP stores the email messages on the server until the user manually deletes those messages.
When retrieving email messages, which protocol allows for easy, centralized storage and backup of emails that would be desirable for a small- to medium-sized business?
IMAP is preferred for small-to medium-sized businesses as IMAP allows centralized storage and backup of emails, with copies of the emails being forwarded to clients
Two students are working on a network design project. One student is doing the drawing, while the other student is writing the proposal. The drawing is finished and the student wants to share the folder that contains the drawing so that the other student can access the file and copy it to a USB drive. Which networking model is being used?
In a peer-to-peer (P2P) networking model, data is exchanged between two network devices without the use of a dedicated server.
What do the client/server and peer-to-peer network models have in common?
In both the client/server and peer-to-peer network models, clients and servers exist. In peer-to-peer networks, no dedicated server exists, but a device can assume the server role to provide information to a device serving in the client role.
What protocols operate at the Network Layer
Internet Protocol
What is a Hybrid P2P network
Is one in which a server supplies index information that enables a peer to locate resources on other peers.
What is the Purpose of the Simple Mail Transfer Protocol
Its used to send mail from the client to the server
Which application layer protocol is used to provide file-sharing and print services to Microsoft applications?
SMB is used in Microsoft networking for file-sharing and print services.
Which two actions are taken by SMTP if the destination email server is busy when email messages are sent?
SMTP tries to send the messages at a later time SMTP periodically checks the queue for messages and attempts to send them again.
What three protocols do email users uses and servers use to process email?
Simple Mail Transfer Protocol TCP Port 25 Post Office Protocol TCP Port 110 Internet Message Protocol TCP Port 143
What protocols operates at the Transport layer
TCP and UDP
Which statement is true about FTP?
The client can download data from or upload data to the server.
Which command is used to manually query a DNS server to resolve a specific host name?
The nslookup command was created to allow a user to manually query a DNS server to resolve a given host name.
What is the Puorpose of Domain Name System TCP/UDP Port Number 53
Translates Domain Name into IP address
The File Transfer Protocol (FTP) is a commonly used application layer protocol. True or False? In FTP transactions, an FTP client uses the pull method to download files from an FTP server.
True, FTP allows for data transfers between a client and a server. During data transfers, FTP client downloads (pulls) data from the server. The FTP client can also upload (push) data to the server.
Which two tasks can be performed by a local DNS server?
Two important functions of DNS are to (1) provide IP addresses for domain names such as www.cisco.com (2) forward requests that cannot be resolved to other servers in order to provide domain name to IP address translation.
The purpose of the Command: tracert
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.
What type of information is contained in a DNS MX record?
mail exchange(MX) messages, are used to map a domain name to several mail exchange servers that all belong to the same domain.
Which phrase describes an FTP daemon
An FTP server runs an FTP daemon, which is a program that provides FTP services. End users who request services must run an FTP client program.
Which three layers of the OSI model provide similar network services to those provided by the application layer of the TCP/IP model?
Application Presentation Session The Lower layers of the OSI model are more concerned with data flow.
What TCP/IP layer supports the exchange of data between programs running on the source and destination host
The Application Layer: -Closest to the end user -Enables users to send/ receive data with ease -Acts as an interface between the Application Layer and underlying networks -Helps exchange data between programs running on Source and Destination Host
What is a common protocol that is used with peer-to-peer applications such as WireShare, Bearshare, and Shareaza?
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.
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?
The ISP uses the HTTP protocol in conjunction with hosting web page FTP protocol with file transfers SMTP with e-mail
What is true about the Server Message Block protocol?
The Server Message Block protocol is a protocol for file, printer, and directory sharing. Clients establish a long term connection to servers and when the connection is active, the resources can be accessed. Every SMB message has the same format.
Which TCP/IP model layer is closest to the end user?
The application layer of the TCP/IP model is closest to the end user. End users use applications to interact with and use the network. Application layer protocols are used to communicate and exchange messages with other network devices and applications.
What part of the URL, http://www.cisco.com/index.html, represents the top-level DNS domain?
The components of the URL http://www.cisco.com/index.htm are as follows: http = protocol www = part of the server name cisco = part of the domain name index = file name com = the top-level domain
The purpose of the Command: Ping
Was created to test reachability on a network and can resolve a hostname by automatically querying a DNS server.
What is an example of network communication that uses the client-server model?
When a user types a domain name of a website into the address bar of a web browser, a workstation needs to send a DNS request to the DNS server for the name resolution process. This request is a client/server model application.
