Exam Essentials ( Network+ Chapter 2 )

Exam Essentials
Be able to specify the main features—including speed, access method, topology, and media—of various network technologies, such as 802 standards and FDDI. You should be able to differentiate between the various networking technologies when studying for the exam. Refer to Table 2.3 for help.

Be able to identify a MAC address. A MAC address on a network is a 12-digit hexadecimal number in the format xx:xx:xx:xx:xx:xx, where x is a number from 0 to 9 or a letter from A to F.

Be able to identify the seven layers of the OSI model and describe their functions. 
The seven layers of the OSI model (from the bottom to top—or layer 1 to layer 7) are the Physical layer, Data Link layer, Network layer, Transport layer, Session layer, Presentation layer, and Application layer.

Know how to differentiate between the IP, IPX, NetBEUI, and AppleTalk/AppleTalk over IP protocols when it comes to routing, addressing schemes, interoperability, and naming conventions.
TCP/IP uses the likes of RIP or OSPF as routing protocols, uses a dotted decimal notation (four sets of numbers, each from 0 to 255) for the addressing, is completely interoperable,
and uses DNS for host naming.

IPX, on the other hand, uses IPX RIP and NLSP for routing information, uses a unique 20-digit address (incorporating the MAC address) for the station address, interoperates with several different
operating systems (but not as many as TCP/IP), and uses NDS for host naming.

NetBEUI isn’t routable or as flexible, nor does it have as many features, but it does offer performance on a LAN segment. Addressing and naming are completely automatic (naming does
require a user to enter a computer name).
Finally, AppleTalk does have routing protocols (RTMP) and uses an automatic addressing scheme. It requires only that the user name the computer when enabling AppleTalk. It is by far the simplest protocol, but it has the lowest performance and the least interoperability. Apple-Talk over IP is a form of tunneling for AppleTalk traffic so AppleTalk devices across the Internet can communicate using that public network, but AppleTalk itself is compatible with neither IP nor the Internet.

Be able to explain the issues that must be considered when multiple protocols are running at the same time. When running multiple protocols, not only are you using more memory on a computer, you’re adding a level of complexity to the network that is multiplied by the number of stations  that you add. It is better to run the fewest protocols possible. Some issues you will see include running out of memory, program confusion, stations unable to communicate (each is running a different protocol), and network congestion.

Identify the OSI layers at which hubs, switches, bridges, WAPs, routers, and network interface cards operate. Hubs operate at the Physical layer for the most part. Switches can operate at
many different layers (up to layer 5), but the lowest common denominator for all network switches is OSI layer 2 (Data Link layer). Bridges are relatively simple devices and operate primarily
at the Data Link layer. Routers are more complex devices, but because all they do is route packets, they operate at layer 3 (Network layer). Finally, network interface cards (NICs) operate

at the Physical and Data Link layers.

Review Questions

1. Which layer of the OSI model ensures reliable, end-to-end communications?
A. Network
B. Transport
C. Session
D. Presentation

2. Which layer of the OSI model provides routing functionality?
A. Transport
B. Data Link
C. Physical
D. Network

3. Which layer of the OSI model translates the data from upper-layer protocols into electrical signals and places them on the network media?
A. Physical
B. Transport
C. Data Link
D. Network

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?
A. 802.1
B. 802.2
C. 802.3
D. 802.5

5. Which one of the following devices will not propagate broadcasts from one of its interfaces to another?
A. Hub
B. Switch
C. Repeater
D. Router

6. You are installing a Windows XP–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?
A. Workstation A
B. Workstation B
C. Neither
D. Both

7. You are installing a Windows XP–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?
A. Workstation A
B. Workstation B
C. Neither
D. Both

8. Which device increases the number of collision domains while decreasing the average number of nodes per collision domain?
A. Hub
B. Transceiver
C. Switch
D. NIC

9. Which of the following protocols use a connectionless transport? (Choose all that apply.)
A. HTTP
B. TCP
C. TFTP
D. IP
E. NetBIOS

10. Which protocols use a connection-oriented transport?
A. UDP
B. NetBIOS
C. HTTP
D. TFTP

11. Which name resolution system is implemented with TCP/IP by default?
A. DNS
B. NDS
C. SND
D. WINS

12. Which OSI model layer has both a MAC sublayer and an LLC sublayer?
A. Physical
B. Transport
C. Network
D. Data Link

13. Which OSI model layer is responsible for establishing, maintaining, and breaking down dialog?
A. Application
B. Gateway
C. Session
D. Network

14. Which OSI layer is responsible for formatting data based on a standard syntax and for character- set conversion?
A. Transport
B. Network
C. Presentation
D. Session

15. Which OSI layer is responsible for building and tearing down packets?
A. Network
B. Transport
C. Data Link
D. Physical

16. The two halves of a MAC address are referred to as the 
A. TCP and IP
B. OUI and device ID
C. OUI and IP
D. Device ID and IP

17. Which of the following directory services are hierarchical in design? (Choose all that apply.)
A. Novell NetWare Bindery
B. Microsoft Windows AD
C. Linux password shadow file
D. NT domain

18. You are the administrator of a 100-node Ethernet network. Your users are complaining of slow network speeds. What could you replace your hub with to increase your network throughput?
A. Router
B. Bridge
C. Switch
D. NIC

19. At which OSI model layer do routers primarily operate?
A. Physical
B. Data Link
C. Transport
D. Network

20. Which of the following is a MAC address?
A. 199.165.217.45
B. 00076A:01A5BBA7FF60
C. 01:A5:BB:A7:FF:60

D. 311 S. Park St.