CCNA CHAPTER 7 VER:4.1

Answer of CCNA Discovery : Version 4.1 by -NoNaMeZzz-

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 User2@cisco.com. 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

10.

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 172.16.5.10.
• If the ping http://www.cisco.com command is issued, the file will be checked for the Cisco web 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
• HTTP
ICMP
PPP
Telnet
• SMTP

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?

SNMP
FTP
• SMTP
HTTPS

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 – 192.168.1.17:80 ; Destination – 192.168.2.39:80
Source – 192.168.1.17:80 ; Destination – 192.168.2.39:1045
• Source – 192.168.1.17:1045 ; Destination – 192.168.2.39:80
Source – 192.168.1.17:1045 ; Destination – 192.168.2.39:1061

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.

21.

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

22.
Which three fields do a TCP header and UDP header have in common? (Choose three.)

• checksum
• destination port
• source port