Review Questions

1. 

Which layer of the OSI model ensures reliable, end-to-end communications?

  1. Network

  2. Transport

  3. Session

  4. Presentation

b.of the layers listed, the only osi layer that is responsible for reliable, end-to-end communications is the transport layer. the network layer is responsible for logical network addresses, the session layer is responsible for opening and maintaining session information, and the presentation layer is responsible for how data looks to the upper layer(s).

2. 

Which layer of the OSI model provides routing functionality?

  1. Transport

  2. Data Link

  3. Physical

  4. Network

d.of the osi model layers listed, the network layer is the only one that is responsible for routing information, because it contains information for logical network addressing.

3. 

Which layer of the OSI model translates the data from upper-layer protocols into electrical signals and places them on the network media?

  1. Physical

  2. Transport

  3. Data Link

  4. Network

a.the physical layer, as its name suggests, is the layer responsible for placing electrical transitions on the physical media. the other layers are all upper layers.

4. 

You are a consultant designing a network for a company with more than 1000 users. Which 802 standard would you implement to ensure that bandwidth would be sufficient and equal without bridging or additional segments?

  1. 802.1

  2. 802.2

  3. 802.3

  4. 802.5

d.the 802.5 standard is similar to the token ring technology developed by ibm. that technology scales well and could handle more than 1000 users without bridging or additional segments. also, the performance would be better than that of any of the other technologies listed.

5. 

You have a limited budget and need to design a network for 50 users. Which 802 standard would you implement?

  1. 802.1

  2. 802.3

  3. 802.5

  4. 802.9

b.the 802.3 standard (similar to ethernet) would work best in this situation because it is flexible, simple to implement, and, most importantly, cheaper than the other technologies listed.

6. 

You are installing a Windows 95/98–based TCP/IP network. You accidentally set workstation B to the same IP address as workstation A. Which workstation(s) will receive an error message?

  1. Workstation A

  2. Workstation B

  3. Neither

  4. Both

d.through broadcasts, both workstations will detect if there is a duplicate ip address on the network and will display error messages to that effect.

7. 

You are installing a Windows 95/98–based TCP/IP network. You accidentally set workstation B to the same IP address as workstation A. Which workstation(s) will have a valid IP address?

  1. Workstation A

  2. Workstation B

  3. Neither

  4. Both

a.because workstation a had a valid ip address to begin with, windows takes a first come, first served approach with the ip addresses and lets workstation a keep its ip address. workstation b detects that a already has it and just deactivates that address.

8. 

Unix uses which method to resolve Transport layer names into logical network addresses?

  1. WINS

  2. NDS

  3. DNS

  4. TRS

c.domain name services (dns) is the primary method most unix implementations use to map logical names to network (ip) addresses. although some versions of unix can use wins and nds, dns is the preferred method.

9. 

Which of the following protocols use a connectionless transport? (Choose all that apply.)

  1. HTTP

  2. TCP

  3. TFTP

  4. IP

  5. NetBIOS

c, e.answers c and e, tftp and netbios, both use a connectionless transport. answer b is, in fact, a connection-oriented transport protocol. http uses tcp, so it is therefore connection-oriented. and ip is a network layer protocol.

10. 

Which protocols use a connection-oriented transport?

  1. UDP

  2. NetBIOS

  3. HTTP

  4. NLSP

c.of all the protocols listed, http is the only one that uses a connection-oriented transport protocol (tcp). the others use connectionless transport.

11. 

Which name resolution system is implemented with TCP/IP by default?

  1. DNS

  2. NDS

  3. SND

  4. WINS

a.although wins is a name resolution that does use tcp/ip, it works only on windows-based networks. the only true name resolution system that almost every tcp/ip network uses is dns.

12. 

Which OSI model layer has both a MAC sublayer and an LLC 12 sublayer?

  1. Physical

  2. Transport

  3. Network

  4. Data Link

d.the data link layer is divided into two sublayers: the mac sublayer and an llc sublayer. the other layers aren t normally subdivided.

13. 

Which OSI model layer is responsible for establishing, maintaining, and breaking down dialog?

  1. Application

  2. Gateway

  3. Session

  4. Network

c.the session layer is responsible for establishing, maintaining, and breaking down dialog.

14. 

Which OSI layer is responsible for network services such as messaging and file transfer?

  1. Transport

  2. Network

  3. Application

  4. Session

c.the services listed are all network applications, and the only layer that provides network application services is the application layer.

15. 

Which OSI layer is responsible for building and tearing down packets?

  1. Network

  2. Transport

  3. Data Link

  4. Physical

a.the network layer is responsible for packaging data into packets. the other layers use different terms for data packages, such as frames.

16. 

On an Ethernet network, every station must have a _______________.

  1. Hub

  2. NIC

  3. Switch

  4. Transceiver

b.all of the devices listed, except the nic, are external devices. additionally, there is usually only one of each of the other devices on a network, but there has to be at least one nic per station.

17. 

Which type of hub doesn’t require power?

  1. Active

  2. Passive

  3. Intelligent

  4. Switched

b.passive hubs simply make physical connections, and thus are usually unpowered. all of the other types listed require power.

18. 

You are the administrator of a 100-station Ethernet network. Your users are complaining of slow network speeds. What could you replace your hub with to increase your network throughput?

  1. Router

  2. Bridge

  3. Switch

  4. NIC

c.a switch would increase performance by making virtual, direct connections between sender and receiver. bridges and routers actually decrease performance because these devices introduce latency into the communication. replacing the hub with a nic just can t be done.

19. 

At which OSI model layer do routers operate?

  1. Physical

  2. Data Link

  3. Transport

  4. Network

d.because routers deal with logical network addresses, they operate at the network layer.

20. 

Which of the following is a MAC address?

  1. 199.165.217.45

  2. 00076A: 01A5BBA7FF60

  3. 01:A5:BB:A7:FF:60

  4. 311 S. Park St.

c.mac addresses use a 12-digit hexadecimal number that is separated into six pairs of hex numbers. the only one that corresponds to that format is answer c.

Answers

1. 

B.  Of the layers listed, the only OSI layer that is responsible for reliable, end-to-end communications is the Transport layer. The Network layer is responsible for logical network addresses, the Session layer is responsible for opening and maintaining session information, and the Presentation layer is responsible for how data “looks” to the upper layer(s).

2. 

D.  Of the OSI model layers listed, the Network layer is the only one that is responsible for routing information, because it contains information for logical network addressing.

3. 

A.  The Physical layer, as its name suggests, is the layer responsible for placing electrical transitions on the physical media. The other layers are all upper layers.

4. 

D.  The 802.5 standard is similar to the Token Ring technology developed by IBM. That technology scales well and could handle more than 1000 users without bridging or additional segments. Also, the performance would be better than that of any of the other technologies listed.

5. 

B.  The 802.3 standard (similar to Ethernet) would work best in this situation because it is flexible, simple to implement, and, most importantly, cheaper than the other technologies listed.

6. 

D.  Through broadcasts, both workstations will detect if there is a duplicate IP address on the network and will display error messages to that effect.

7. 

A.  Because workstation A had a valid IP address to begin with, Windows takes a first come, first served approach with the IP addresses and lets Workstation A keep its IP address. Workstation B detects that A already has it and just deactivates that address.

8. 

C.  Domain Name Services (DNS) is the primary method most Unix implementations use to map logical names to network (IP) addresses. Although some versions of Unix can use WINS and NDS, DNS is the preferred method.

9. 

C, E.  Answers C and E, TFTP and NetBIOS, both use a connectionless transport. Answer B is, in fact, a connection-oriented transport protocol. HTTP uses TCP, so it is therefore connection-oriented. And IP is a Network layer protocol.

10. 

C.  Of all the protocols listed, HTTP is the only one that uses a connection-oriented transport protocol (TCP). The others use connectionless transport.

11. 

A.  Although WINS is a name resolution that does use TCP/IP, it works only on Windows-based networks. The only true name resolution system that almost every TCP/IP network uses is DNS.

12. 

D.  The Data Link layer is divided into two sublayers: the MAC sublayer and an LLC sublayer. The other layers aren’t normally subdivided.

13. 

C.  The Session layer is responsible for establishing, maintaining, and breaking down dialog.

14. 

C.  The services listed are all network applications, and the only layer that provides network application services is the Application layer.

15. 

A.  The Network layer is responsible for packaging data into packets. The other layers use different terms for data packages, such as frames.

16. 

B.  All of the devices listed, except the NIC, are external devices. Additionally, there is usually only one of each of the other devices on a network, but there has to be at least one NIC per station.

17. 

B.  Passive hubs simply make physical connections, and thus are usually unpowered. All of the other types listed require power.

18. 

C.  A switch would increase performance by making virtual, direct connections between sender and receiver. Bridges and routers actually decrease performance because these devices introduce latency into the communication. Replacing the hub with a NIC just can’t be done.

19. 

D.  Because routers deal with logical network addresses, they operate at the Network layer.

20. 

C.  MAC addresses use a 12-digit hexadecimal number that is separated into six pairs of hex numbers. The only one that corresponds to that format is Answer C.




Network+ Study Guide
Network+ Study Guide
ISBN: 470427477
EAN: N/A
Year: 2002
Pages: 151

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