CS 357 - Computer Networks I

Assignments 5

Due Wednesday June 19, 2002 @ 8:30 a.m.
Due on the CS 357 locker No. 103, MC building, ground floor (beside the elevator)
Do not forget to write CLEARLY your name, your student number, and sign the submission form


  1. Find:-
    • the class
    • the network number, if any,
    • the connection address (suffix), if any, and
    • the direct broadcast address, if any.
    of each of the following addresses?

    (a) 10011111 10001111 11111100 11001111
    (b) 11101111 10001111 11111100 11001111
    (c) 11110111 10001111 11111100 11001111
    (d) 00011111 10001111 11111100 11001111
    (e) 11011111 10001111 11111100 11001111
    (f) 60.23.145.90
    (g) 120.34.78.7
    (h) 180.7.3.8
    (i) 240.6.8.4
    (j) 250.76.9.23

    Please put your answer in a table form

  2. In IPv4, if an IP datagram contains two bytes in the OPTIONS field and two bytes in the DATA field:
    - What will be the value of the H.LEN and TOTAL LENGTH fields in this IP datagram header?
    - Explain Why?
  3. In IPv4, suppose an IP datagram arrived at a router. This IP datagram has:
    - TOTAL LENGTH field = 474
    - FLAGS filed = 0
    - FRAGMENT OFFSET field = 0
    - TIME TO LIVE = 7
    - The length of the header is 20 bytes

    Suppose that this datagram will be forwarded to another network which has a MTU of 247 bytes.

    • Show the fragments that the router will create and specify the values of the VER, H.LEN, TOTAL LENGTH, FLAGS, FRAGMENT OFFSET, and TIME TO LIVE fields in the header of each fragmented datagram.
    • Is your answer is unique? Why?