Discovery 2 : Chapter 7

1. Which two statements are true about the OSI and TCP/IP models? (Choose two.) 
• The two bottom layers of the TCP/IP model make up the bottom layer of the OSI model. 
• The TCP/IP model is a theoretical model and the OSI model is based on actual protocols. 
• The OSI network layer is comparable to the Internet layer of the TCP/IP model. 
• The TCP/IP model specifies protocols for the physical network interconnection. 
• The TCP/IP model is based on four layers and the OSI model is based on seven layers. 

2. To meet customer expectations, an ISP must guarantee a level of service that is based on what two factors? (Choose two.) 
• accessibility 
• adaptability 
• availability 
• reliability 
• scalability 

3. User1 is sending an e-mail to What are two characteristics of the process of sending this data? (Choose two.) 
• It utilizes TCP port 110. 
• A TCP connection is established directly between the User1 and User2 client computers in order to send the e-mail message. 
• It utilizes a store and forward process. 
• The same application layer protocol is used to send the e-mail and retrieve it from the destination server. 
• SMTP is used to send the e-mail message to the mail servers. 

4. Refer to the exhibit. Host1 is in the process of setting up a TCP session with Host2. Host1 has sent a SYN message to begin session establishment. What happens next? 
• Host1 sends an ACK message to Host2. 
• Host1 sends a SYN message to Host2. 
• Host1 sends a SYN-ACK message to Host2. 
• Host2 sends an ACK message to Host1. 
• Host2 sends a SYN message to Host1. 
• Host2 sends a SYN-ACK message to Host1. 

5. What are three characteristics of network reliability? (Choose three.) 
• Redundant hardware provides enhanced reliability. 
• Reliability is measured as a percent. 
• Reliability is the responsibility of the ISP customers. 
• Fault tolerance is a measure of reliability. 
• The longer the MTBF, the greater the reliability. 

6. Which two statements describe the FTP protocol? (Choose two.) 
• It uses well-known port 23. 
• The protocol interpreter is responsible for the data transfer function. 
• In passive data connections, the FTP client initiates the transfer of data. 
• It requires two connections between client and server. 
• FTP servers open a well-known port on the client machine. 

7. What is the function of the TCP three-way handshake? 
• It enables the synchronization of port numbers between source and destination hosts. 
• It immediately triggers the retransmission of lost data. 
• It synchronizes both ends of a connection by allowing both sides to agree upon initial sequence numbers. 
• It identifies the destination application on the receiving host. 

8. What are three characteristics of HTTPS? (Choose three.) 
• It uses a different client request-server response process than HTTP uses. 
• It specifies additional rules for passing data between the application and data link layers. 
• It supports authentication. 
• It allows more simultaneous connections than HTTP allows. 
• It encrypts packets with SSL. 
• It requires additional server processing time. 

9. Which DNS zone resolves an IP address to a qualified domain name? 
• dynamic lookup 
• forward lookup 
• resolution lookup 
• reverse lookup 

What type of update allows client computers to register and update their resource records with a DNS server whenever changes occur? 
• dynamic 
• zone transfer 
• local recursive query 
• root domain query 
• top-level domain query 

11. Refer to the exhibit. Which two statements are true about this file? (Choose two.) 
• If the gateway address changes, the file will be updated dynamically. 
• The command ping fileserv will use IP address 
• If the ping command is issued, the file will be checked for the Ciscoweb server IP address before DNS is queried. 
• The file must be created by the user if it is to be used by a workstation. 
• Name to IP address mappings are added to the file after they are received from DNS. 

12. Which two tasks are the responsibility of the local DNS server? (Choose two.) 
• maintaining a large number of cached DNS entries 
• maintaining the ISP server 
• mapping name-to-IP addresses for internal hosts 
• forwarding name resolution requests to a caching-only server 
• forwarding all name resolution requests to root servers on the Internet 

13. What are three unique characteristics of UDP? (Choose three.) 
• connection oriented 
• full-duplex operation 
• low overhead 
• no flow control 
• no error-recovery function 
• reliable transmission 

14. A manufacturing company is looking into subscribing to services from a new ISP. The company requires hosted world wide web, file transfer, and e-mail services. Which three protocols represent the key application services that are required by the company? (Choose three.) 
• FTP 
• PPP 
• Telnet 

15. Which two options correctly match protocol and well-known port number? (Choose two.) 
• DNS - 25 
• FTP - 110 
• HTTP - 80 
• POP3 - 25 
• SMTP - 25 

16. Within TCP, what combination makes up a socket pair? 
• source port with destination port 
• source IP address with destination port 
• source IP address and destination IP address 
• source IP address and port with a destination IP address and port 

17. Which protocol is used to send e-mail, either from a client to a server or from a server to another server? 
• FTP 

18. Refer to the exhibit. The PC is requesting HTTP data from the server. What is a valid representation of source and destination sockets for this request? 
• Source - ; Destination - 
• Source - ; Destination - 
• Source - ; Destination - 
• Source - ; Destination - 

19. What type of DNS server is typically maintained by an ISP? 
• caching-only 
• root 
• second-level 
• top-level 

20. A client is communicating with a server on a different segment of the network. How does the server determine what service is being requested by the client? 
• The server will apply the default service configured in directory services. 
• The server will use ARP to discover the appropriate service from the local router. 
• The server will send a request to the client asking for the appropriate service. 
• The server will determine the appropriate service from the destination port field. 

When a host is communicating with multiple applications on the same server at the same time, which of the following will have the same value for each session? (Choose two.) 
• IP address 
• MAC address 
• session number 
• sequence number

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