CISCO CHAPTER 10

Select three protocols that operate at the Application Layer of the OSI model. (Choose three.)

1. FTP 2. POP3 3. DHCP

Which two actions are taken by SMTP if the destination email server is busy when email messages are sent? (Choose two.)

1. SMTP tries to send the messages at a later time. 2. SMTP periodically checks the queue for messages and attempts to send them again. (The destination email server may be offline or busy when email messages are sent. In either of these cases, SMTP spools messages to be sent at a later time. Periodically, the server checks the queue for messages and attempts to send them again. The message is returned to the sender as undeliverable if it is still not delivered after a predetermined expiration time.)

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

1. FTP 2. HTTP 3. SMTP

end device address

A

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. (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. The eMule application is P2P. Sharing a printer on a workstation is a peer-to-peer network. Using ARP is just a broadcast message sent by a host.)

canonical name

CNAME

mail exchange record

MX

What is an advantage for small organizations of adopting IMAP instead of POP?

Messages are kept in the mail servers until the client manually deletes them. (IMAP and POP are protocols that are used to retrieve email messages. The advantage of using IMAP instead of POP is that when the user connects to an IMAP-capable server, copies of the messages are downloaded to the client application. IMAP then stores the email messages on the server until the user manually deletes those messages.)

authoritative name server

NS

peer-to-peer network

X. requires a specific user interface X. devices can only function in one role at a 2. client and server roles are set on a per request basis 3. no dedicated server is required P.s. 1. they do not require formalized accounts or permission 2. they are best used in limited situations

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 (SMB and FTP are both client/server protocols. Although they both provide file sharing, in SMB, clients establish a much longer term connection to servers than FTP does. Only SMB provides printer services.)

A DHCP-enabled client PC has just booted. During which two steps will the client PC use broadcast messages when communicating with a DHCP server? (Choose two.)

1. DHCPDISCOVER 2. DHCPREQUEST (All DHCP messages between a DHCP-enabled client and a DHCP server are using broadcast messages until after the DHCPACK message. The DHCPDISCOVER and DHCPREQUEST messages are the only messages that are sent by a DHCP-enabled client. All DHCP messages between a DHCP-enabled client and a DHCP server use broadcast messages when the client is obtaining a lease for the first time.)

peer-to-peer application

1. a background service is required devices can only function in one role at a time 2. requires a specific user interface

Which two tasks are functions of the presentation layer? (Choose two.)

1. compression 2. encryption (The presentation layer deals with common data format. Encryption, formatting, and compression are some of the functions of the layer. Addressing occurs in the network layer, session control occurs in the session layer, and authentication takes place in the application or session layer.)

What are two characteristics of peer-to-peer networks? (Choose two.)

1. decentralized resources 2. resource sharing without a dedicated server

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.)

1. session layer 2. application layer 3. presentation layer (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.)

Which three statements describe a DHCP Discover message? (Choose three.)

1.The destination IP address is 255.255.255.255. 2. The message comes from a client seeking an IP address. 3. All hosts receive the message, but only a DHCP server replies. (When a host configured to use DHCP powers up on a network it sends a DHCPDISCOVER message. FF-FF-FF-FF-FF-FF is the L2 broadcast address. A DHCP server replies with a unicast DHCPOFFER message back to the host.)

What is true about the Server Message Block protocol?

Clients establish a long term connection to servers. (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. The use of SMB differs from FTP mainly in the length of the sessions. SMB messages can authenticate sessions.)

a message that is used to acknowledge that the lease is successful

DHCPACK

a message that is used to locate any available DHCP server on a network

DHCPDISCOVER

a message that is used to when an offered lease is no longer valid.

DHCPOFFER

a message that is used to identify both the specific DHCP server and the lease that the client is accepting.

DHCPREQUEST

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

HTTP

What is the acronym for the protocol that is used when securely communicating with a web server?

HTTPS (Hypertext Transfer Protocol Secure (HTTPS) is the protocol that is used for accessing or posting web server information using a secure communication channel.)

<output> >cisco.netacad.net Server: Unknown Address:192.168.0.1 Non-nuthoritative answer: Name: cisco.netacad.net Address: 72.163.6.223 <output omitted> Refer to the exhibit. What command was used to resolve a given host name by querying the name servers?

NSLOOKUP (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.​)

Open the PT Activity. Perform the tasks in the activity instructions and then answer the question. Which PC or PCs are sending FTP packets to the server?

PC_2 (After you view the details of the packets that are being transferred between each PC and the server, you will see that the PC that is using a destination port number of 20 or 21 is the PC using the FTP service. PC_2 has an outbound port number of 21 to create an FTP control session with the server at 192.168.1.253.)

A user accessed the game site www.nogamename.com last week. The night before the user accesses the game site again, the site administrator changes the site IP address. What will be the consequence of that action for the user?

The user will access the site without problems. (If the game site administrator decides to change the IP address of the site www.nogamename.com, it is transparent to the user because the domain name will remain the same.)

Which phrase describes an FTP daemon?

a program that is running on an FTP server (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 DNS server in the DNS hierarchy would be considered authoritative for the domain name records of a company named netacad?

netacad.com (In the DNS hierarchy, the top level domain servers (.com, .gov, .edu, etc.) contain records of second-level domain servers (netacad.com, whitehouse.gov, etc.). The second-level domain name server (netacad.com) is an authoritative DNS server because it maintains all records for the netacad company. The mx.netacad.com and www.netacad.com are either A records, CNAME records, or MX records maintained by the netacad.com DNS server.)