Network Management          CS 458/558                                       NAME_______________

Spring 2000                           Midterm Exam                                   Dr. Wayne Summers

 

Read each question carefully before you answer.  Work at a steady pace, and you should have ample time to finish.  Make sure your name is on your paper before you turn it in. 

 

I. Multiple Choice: Write the letter of the best answer. (2 pts. Each)

 

___e_____ 1. Which statements are true about TCP/IP?

a)     TCP/IP is routable

b)     TCP/IP is the language of the Internet

            c) You can interconnect with more networks if you are using TCP/IP

            d) TCP/IP accommodates a wide range of network hardware, operating systems, and applications

e) All of the above are true

 

___a_____ 2. Which networking protocol would be easiest to configure for a 10-workstation Windows peer-to-peer network?

a) NetBEUI                                                    b) IPX/SPX

            c) TCP/IP                                                       d) SNA

e) ATM

 

____a____ 3. Why do bridges provide better network performance than repeaters?

a) They analyze packets and only forward them on required ports                                            b) They use faster hardware than repeaters

c)      They ignore bad input signals

 

___d_____ 4. Which is not a routable protocol?

a) IP                            b) IPX             c) AppleTalk  d) NetBEUI     e) none of these

 

___d_____ 5. A star network is more expensive to set up than a bus network because:

a)     Star hubs are very expensive

b)     Star networks require expensive connectors at the end of each cable

c)      Star-based NICs are more expensive than bus-based NICS

d)     Star networks require more cable than bus networks

 

____c____ 6. In a bus network, if one computer is not able to communicate with any other computer on the network, but all other computer communicate fine, what is the most likely cause of the problem?

a)     The terminator closest to the computer is not communicating

b)     The segment of cable that connects the non-communicating computer to its nearest neighbor is defective

c)      The NIC board in the computer is not communicating

d)     The length of cable for the network exceeds maximum length

 

____d____ 7. You are the network administrator for a small company that has grown steadily over the years. You have a 10Base-T network; with each new employee, you add a new connection. Your network currently has 150 computers connected to it, and you are getting complaints about how slow the network is at certain times of the day. You test the network at lunch and find no problems. What is the most likely cause of the network slowdown?

a)     The network servers are overloaded

b)     You have exceeded the maximum cable length for your 10Base-T network, which causes intermittent problems

c)      You have too many hubs on the network, which causes delays

d)     Your large network is susceptible to network traffic

 

___c_____ 8. What OSI layer determines the route a packet will take through a network?

a) Data Link Layer                                        b) Presentation Layer

            c) Network Layer                                           d) Physical Layer

 

___a_____ 9. Which connection mode is faster when there are little or no errors?

a)     Connectionless-oriented mode

b)     Connection-oriented mode

c)      There is no difference

 

___b_____ 10. Which OSI layer includes cable and connectors?

a) Data Link                                                  b) Physical

            c) Network                                                      d) Transport

 

___a_____ 11. Which layer defines the network topology?

a) Data Link                                                  b) Physical

            c) Network                                                      d) Transport

 

__d______ 12.  What is the best way to attach individual wires to a patch panel or the back of a wall jack?

a) Velcro straps                                             b) Twist ties

            c) staple gun                                                  d) punch tool

 

___b_____ 13.  Before networks, what did people use to transfer files?

a) Protocols   b) Sneakernet            c) NICs           d) Ethernet

 

___d_____ 14.  Which device simply regenerates incoming signals?

a) gateway                 b) router          c) brouter        d) repeater

 

__a______ 15.  Which OSI layer translates logical network addresses into physical addresses?

a) Data Link                                                  b) Session

            c) Network                                                      d) Presentation

            e) Application

 

___e_____ 16.  What is a MAC address on an Ethernet Network?

a)     a logical address that identifies the workstation

b)     an address assigned by the systems administrator

c)      a workstation's logical domain address

d)     a physical address assigned by the systems administrator

e)     a physical address assigned by the NIC manufacturer

 

___a_____ 17.  You are troubleshooting a Thinnet LAN. Which of the following cable lengths that you found is/are legal?

a) 150 meters            b) 200 meters            c) 500 meters            d) all of these

           

___c_____ 18.  You are designing an Ethernet network wired with Category 5 twisted-pair copper cable. The cables used

a) consist of only two wires              b) consist of two pairs of wires

c) consist of four pairs of wire                      d) don't need to connect to a hub

           

___d_____ 19.  Twisted-pair cable is the most common LAN cable because:

a)     low cost                                                   

b)     ease of installation

c)      high availability of compatible network components                                      

d)     all of these

            e) none of these

 

___b_____ 20.  ARP involves which two types of information?

a)     Network number and host ID

b)     Network address and data link address

c)      Logical node names and IP address

d)     Protocol type and frame number

           

___a_____ 21.  Microsoft provides updates and patches to some of its programs on the Internet. Which protocol might you use to download the necessary files?

a) FTP                        b) UDP                       c) IP                            d) DNS

           

___a,c_____ 22.  What are the parts of a network address? (Select all)

a) Host Identifier                                            b) MAC Address      

c) Network Identifier                                      d) physical address

           

____c____ 23.   A packet that is destined for all nodes on a network is known as _____.

a) Multicast                b) Unicast                   c) Broadcast              d) Bandcast

           

_____b___ 24.  What method is used to prevent bridging loops?

a) Manually disable the ports                       b) Spanning Tree Algorithm

c) VLAN                                                         d) IEEE 802.10

           

___b_____ 25.  How many layers of the TCP/IP protocol suite are required for operating a bridge?

a) 0                 b) 2                 c) 3                              d) 4

           

_a,c,d_______ 26.  Which of the following accurately describes the Media Access Control (MAC) address? (Choose all correct answers.)

a) It is a physical number set during the manufacturing process.

b) This address is a layer in a network segment              

c) MAC addresses contain 12 hexadecimal numbers                            

d) Computers use this address to uniquely identify themselves on the network

e) An IP address is one example of this type of address

           

__a______ 27.  When must you change the IP address of a given host on a network segmented with routers?

a) When that computer is moved to a different segment on the network           

b) When the network card is replaced                   

c) When the router is replaced                               

d)  When a bridge is replaced

e) When a switch is replaced

           

____b____ 28.  Which of the followig can cause the complete failure of a bus network?

a) Failure of one station                   b) Break in a cable              

c) Failure of a hub                             d) Bad port on the hub

           

____d____ 29.  What does an active hub do that a passive hub does not?

a) Connect media                             b) Route traffic

c) Segment the network                   d) Repeat the signals

           

____b____ 30.  What type of cable is usually required by fire codes?

a) Voice-grade                                  b) Plenum-grade                  

c) CAT 1                                             d) CAT 3                                e) CAT 5

           

____c____ 31.  If you detect NEXT, what should you do to attempt a quick resolution to the problem?

a) Run a wire map                                         b) Check for attenuation                  

c) Visually inspect the local wiring   d) Replace all RJ-45 jacks

           

___c_____ 32.  Which of the following is not an appropriate cable label?

a) Position 1, Room 12                    b) 2nd floor, atrium                

c) 3rd floor, Jeff’s office                     d)  Room 22, north wall

___d_____ 33.  What is the maximum area that can be served by a star topology with CAT-5 cable?

a) 100 feet by 100 feet                     b) 328 feet by 328 feet

c) 600 meters                                    d) 200 square meters

           

___d_____ 34.  When a network spans two or more buildings, which backbone cable would be best?

a) STP            b) UTP            c) Coaxial                   d) Fiber

           

___c_____ 35.  How is a subnet mask used?

a) To determine whether or not a destination address is correct                       

b) To determine the class of the destination IP address             

c) To determine the network part of an IP address

d) All of these

e) None of these

           

___a_____ 36.  Which of the following is a Class C address?

a) 192.168.17.34                              b) 131.15.45.120

c) 125.76.133.234                            d) 191.234.56.34

           

___b_____ 37.  What is the broadcast address for a node 131.15.46.59?

a) 131.15.46.255                              b) 131.15.255.255               

c) 131.255.255.255                          d) 255.255.46.59

 

___a_____ 38.  You have been given a Class B address of 172.16.0.0. You need to subnet it to 14 subnets. Which subnet mask will give you the most hosts per subnet?

a) 255.255.240.0                              b) 255.255.228.0                 

c) 255.255.248.0                              d) 255.255.255.240

           

           

___c_____ 39.  What is the correct broadcast address for a host with the IP address of 192.168.50.50 using a subnet mask of 255.255.255.240?

a) 192.168.50.15                              b) 192.168.50.48

c) 192.168.50.63                              d)  192.168.50.51

           

___d_____ 40.  You have been given a Class C address of 192.168.10.0/29. Which of the following lists a valid host range?

a) 192.168.10.225 – 192.168.10.230                   

b) 192.168.10.233 – 192.168.10.239

c) 192.168.10.240 – 192.168.10.246

d)  192.168.10.249 – 192.168.10.254

II. Short Answer: Briefly answer the following questions. Undergraduate students need answer only two questions, while graduate students must answer all three. (20 points)

 

41. Your company wants to set up a temporary classroom that will be used once per month for Windows NT training classes. The room must be set up the night before each class begins, it is used for 3 days, and then it is torn down. The class is designed for 15 workstations, one server and a printer. It must be configured as inexpensively as possible. Choose a network topology and cabling and explain the reasons for choosing this topology. Draw a diagram of the layout of the room, label all devices.

 

You can recommend either 10Base-2 or 10BaseT CAT-3, but need to have good reasons for why you choose what you recommended and draw a picture. If you have the printer connected to the network, you need to talk about using either a JetDirect card or hanging the printer off of one of the computers as a printer share.

42. You are a systems administrator for a small company that has grown significantly over the years. You have seven 10Base-T hubs, each with 24 ports. You have just added a new 24-port hub and filled all the ports to support new sales and marketing staff. The network seems very sluggish, and you are receiving many complaints about network speeds. Your boss wants to know what is wrong and how you intend to fix the problem. He read an article about 100-megabit Ethernet and thinks this will solve the problem. What is the most likely cause of the problem and describe an alternative solution? Be specific.

 

Speed is not the problem. You need to discuss the fact there is probably too much traffic on the network and that there may be a violation of the 5-4-3 rule. The simplest solution would be to add a bridge to segment the network. Several of you suggested replacing the hubs with switches. That will certainly work (remember that a switch is a multi-port  bridge), but it a very expensive solution. A compromise that at least one of you noted was to replace the “central” hub with a switch. That may or may not help depending on the network topology.

43. a) Use the OSI model to describe what happens when an e-mail message is transmitted from a computer in LH2 to my office.

 

 

You need to talk about what happens on the OSI model (starting with the Application layer and working your way down to the physical layer) for the client in LH2, the e-mail server in between, and the e-mail client in my office.

 

 

b) Explain how this transmission would be different if the sender was using a computer at home to send the e-mail.

 

Same as above, except that now you need to talk about modems and phone lines at the physical layer between home and the server and you need to talk about what happens at the router. Remember that only the bottom three layers are used for each of the routers.