Now that we are moving into higher layers of the OSI and TCP/IP networking models, we are starting to look at different kinds of hardware and their related concerns. Before, we were mainly concerned with the basics of cables or wireless signals. At this point, we are focusing more on how you build smaller networks -- and combine them into larger networks!

• In your homework hand-in, please answer the following questions:
  1. Explain the terms collision domain and broadcast domain, in the context of an Ethernet network. Explain how hubs, switches, and routers would handle each of these. (Hint: Consider at which layer of the OSI model each of these devices typically operates.)

  2. Design a network topology for your company. You have to network together the following 46 computers:

     5 High-Traffic Servers	S1 - S5
     4 Moderate-Traffic Servers	S6 - S9
     25 Moderate-Traffic Desktops	MT01 - MT25
     12 Low-Traffic Desktops	LT01 - LT12

     These computers are arranged in the following manner, in different areas of the space:
     

     	North S1 , S3 , S5
     West S2 , S6 , S8 , MT01 - MT06		East S4 , S7 , S9 , MT07 - MT19
     Southwest LT01 - LT04 , MT20 - MT23		Southeast LT05 - LT12 , MT24 - MT25

     
     You can assume that no devices are more than 100 meters apart, that you have enough Ethernet cable, and that the cable can handle up to Gigabit speeds.

     You have at your disposal the following items of network hardware:

     • 1 8-Port Gigabit Switch
       
       
     • 2 16-Port FastEthernet Switches with 2 Gigabit Ports each
       
       
       
     • 3 5-Port FastEthernet Switches
       
       
       
       
     • 3 5-Port 10Mbps Hubs
       
       
       
       

     You can assume that all switches are unmanaged. Although I did not name these devices here, you may wish to give them names, for your own convenience and reference.

     Use the switches and hubs to design a network topology for the computers in the network. Create a drawing to accompany this. You should specify such things as...

     • Where the switches/hubs are located -- particularly useful on your drawing.
     • Which switches/hubs are connected to each other, and on what ports. Draw these connections, from port to port, as they occur
     • Which computers -- servers and hosts -- are connected to which switches/hubs.
       • For most devices, it should be enough to list the computer names over/under/beside the devices to indicate their connection.
       • For the 16-Port FastEthernet switches, since each will also have a couple Gigabit ports, you may need to be a bit more detailed in how you depict the connections.
     • Switches/hubs should go only in the North, West, East, Southwest, or Southeast. You can run cables from one area to another to link one switch/hub to another.
     • There should be only one path from one switch/hub to another. Otherwise, you may cause a switching loop!
     • NOTE: You may copy the images of switches/hubs provided above to use in your diagram.

     This may require some creative thinking because you are trying to use the equipment available to you in the most practical manner possible. We do not want to create congestion by giving too little bandwidth to higher-traffic devices, nor do we want to waste bandwidth on lower-traffic devices that do not really need it. In addition to describing and depicting your topology, you should also provided a detailed explanation of how and why you made the decisions you made.

  3. If Network Interface Controllers (NICs), such as Ethernet and wireless adapters, already have unique identifiers in the form of MAC addresses, then why do we even need IP addresses?
  4. A bridge/switch will maintain a table of associations between MAC addresses and its ports. Explain how the bridge/switch "learns" these associations to build the table.
  NOTE: You may wish to include the question text along with your answers, as that can help with organization
• Some of the questions may be answerable using solely the textbook and lecture notes, but others may require some independent research.
• Your hand-in should meet the following specifications:
  • Cite your sources:
    • Do not cite Wikipedia as a source. At most, you can use it to find references that could be used as sources.
    • List any sources consulted. These are sources that significantly influenced your thinking or helped you to work out your ideas -- even if you did not take any specific ideas or points from them.
      • Any sources consulted must be explicitly oriented to science, technology, and/or engineering.
      • Generic, non-technology-specific encyclopaedias, dictionaries, websites, etc. are not valid sources.
      • User-created content -- such as blogs and discussion board posts -- should be vetted for credibility before being used.
    • Any direct quotes (or close paraphrasals) -- in other words, where you are using a specific idea or point from a source -- should be quoted and cited with endnotes
    • There may be some overlap between works consulted and endnotes.
    • If you do consult the textbook and/or lecture notes, those must be cited, as well.
    • There are various official citation styles -- MLA, APA, Chicago, etc. Choose one that you know. At the very least, your citation should make it easy for me to find your source -- and place within the source, if applicable.
    • For web links: Please include the URL so that I have the option to look up your source, if I wish to.
  • Any drawings/diagrams should be clear and easy to understand. Ways to make a drawing include:
    • In some kind of bitmap editing program, such as Paint.
    • Within your word processor, using the drawing utilities.
    • Drawing on paper and...
        * scanning your drawing to an image or...
        * taking a digital photograph of it.
      You would then import this image into your document. In either case, the image must be neat and easy to interpret.
  • Skip lines -- but not an excessive amount! -- to indicate divisions between questions and answers.
  • 0.5-to-1-inch margins
• There is no need to consume several lines at the beginning with information like class, date, etc. Your name will be sufficient.