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¡¡ Homework #5
¡¡ Homework #5.
Due 11:45PM, Jun.1, 2016 Wednesday.
¡¡  Problems ¡¡
please answer the following problems for the chapter 5 of the textbook:
  1. What is a router ?
  2. Routing tables, routing algorithm and packet forwarding are parts of routing, what are they and how are they connected to each other?
  3. What is the difference between connecting networks by switch and by router?
  4. Explain the count to infinity problem in Distance Vector algorithm, describe the problem by an example
  5. Answer to the following questions concerning the network given in next figure. An distance vector based routing algorithm is used in the network.

    a. Draw a table according to the example below. write the routing information of nodes 1 to 5 as (nextnode, distance) pairs when the destination is node 6.

    b. Let's assume that the nodes of the network update their routing tables in parallel simultaneously "step by step" by using distance vector routing algorithm. Fill your table step by step and explain how the information about break between node 3 and 6 propagates in the network, i.e (next node, distance) pairs after each update.
    c. How does using a link state based routing algorithm differ from the situation presented in question b where a distance vector routing algorithm is used?
  6. Consider the subnet of the figure below, Distance Vector Routing is used, and the following vectors have just come in to router C:From B:£¨5£¬0£¬8£¬12£¬6£¬2£©£¬From D£º£¨16£¬12£¬6£¬0£¬9£¬10£©£¬From E£º£¨7£¬6£¬3£¬9£¬0£¬4£©. The measured delays to B, D, and E, are 6, 3, and 5, respectively. What is C¡¯s new routing table? Give both the outgoing line to use and the expected delay.
  7. Explain Shortest Path Algorithm
  8. Compare the differences between Distance Vector Routing and Link State Routing.
  9. What is Maximum Transmission Unit (MTU)? explain the reason and strategy of   fragmentation in a connectionless network like IP?
  10. Draw a figure to show the IPV4 header. (you are required to draw it yourself, don't copy from the Internet or course powerpoint slides).
  11. What is Subnet What is Subnet MASK? Tell me the IP Address, Subnetmask, Default Gateway of the computer you are using currently.
  12. What is CIDR?  Fill blanks in following table with subnet masks corresponding to the CIDR Value.
    Subnet Mask     CIDR Value
    []             [ /24 ]
    [                          ]        [ /25 ]
    [                          ]        [ /26 ]
    [                          ]        [ /27 ]
    [                          ]        [ /28 ]
    [                          ]        [ /29 ]
    [                          ]        [ /30 ]
    [                          ]        [ /31 ]
    [                          ]        [ /32 ]
  13. We are going to subnet the Class C network address by using a subnet mask of Answer the following subquestions.
    • How many subnets?
    • How many hosts per subnet?
    • What are the valid subnets (the start address of each subnet)?
    • What's the broadcast address for each subnet?
    • What are the valid hosts range for each subnet (the first and the last host)?
  14. You have a Class B network and need 29 subnets. What is your mask?
  15. What is the broadcast address of
  16. How many hosts are available with a Class C /29 mask?
  17. What is the subnet for host ID
  18. A large number of consecutive IP address are available starting at Suppose that four organizatons, A,B,C, and D, request 4000,2000,4000, and 8000 addresses, respectively, and in that order. For each of these, give the first IP Address assigned, the last IP address assigned, and the mask in the w.x.y.z/s notation.
  19. A router has the following (CIDR) entries in its routing table:
    Subnet                    Next hop      Interface 0      Interface 1      Router 1
    default                    Router 2
    for each of the following IP addresses, what does the router do if a packet with that address arrives?
  20. The functions of ARP and how does it work?
  21. Give a instruction of OSPF routing Algorithm in detail.
  22. Make a research on the Internet, write a essay about ARP virus (explain how it works and how to prevent it).
¡¡ Notes for Submission ¡¡
¡¡ You must follow the Electronic Submission Guidelines to submit HW5.
You can create your submission by doing the following for e-submission:
  • 1. Create a file containing your answers
  • 2. mail this file to class mailbox, name the mail subject according to the Guidelines