Transcript CS368 Assignment 4 1. (P18-5) Find the class of the following

CS368 Assignment 4
1. (P18-5) Find the class of the following classful IP addresses:
a. 01110111 11110011 10000111 11011101
b. 11101111 11000000 11110000 00011101
c. 11011111 10110000 00011111 01011101
2. (P18-12) Each of the following addresses belongs to a block. Find the first and the
last address in each block.
3. (p18-21) An ISP is granted the block 16.12.64.0/ 20. The ISP needs to allocate
addresses for 8 organizations, each with 256 addresses. a. Find the number and
range of addresses in the ISP block. b. Find the range of addresses for each
organization and the range of unallo-cated addresses. c. Show the outline of the
address distribution and the forwarding table.
4. (P19-2) An IP datagram has arrived with the following partial information in the
header ( in hexadecimal): a. What is the header size? b. Are there any options in
the packet? c. What is the size of the data? d. Is the packet fragmented? e. How
many more routers can the packet travel to?
5. (P19-7) Determine if a datagram with the following information is a first
fragment, a middle fragment, a last fragment, or the only fragment ( no
fragmentation): a. M bit is set to 1 and the value of the offset field is zero. b. M bit
is set to 1 and the value of the offset field is nonzero.
6. (P19- 8. )A packet has arrived in which the offset value is 300 and the payload
size is 100 bytes. What are the number of the first byte and the last byte?
7. (P20-1) Assume that the shortest distance between nodes a, b, c, and d to node y
and the costs from node x to nodes a, b, c, and d are given below:
Day = 5 Dby = 6 Dcy = 4 Ddy = 3
cxa = 2 cxb = 1 cxc = 3 cxd = 1
What is the shortest distance between node x and node y, Dxy, according to the
Bellman- Ford equation?
8. (P20-4) To understand how the distance vector algorithm in Table 20.1 works, let
us apply it to a four- node internet as shown in Figure 20.32. Assume that all
nodes are initialized first. Also assume that the algorithm is applied, one at a time,
to each node respectively ( A, B, C, D). Show that the process converges and all
nodes will have their stable distance vectors.
9. (P20-5) In distance- vector routing, good news ( decrease in a link metric) will
propa-gate fast. In other words, if a link distance decreases, all nodes quickly
learn about it and update their vectors. In Figure 20.33, we assume that a fournode internet is stable, but suddenly the distance between nodes A and D, which
is currently 6, is decreased to 1 ( probably due to some improvement in the link
quality). Show how this good news is propagated, and find the new distance
vector for each node after stabilization.
10. (P20-14) Use Dijkstra’s algorithm (Table 20.2) to find the shortest path tree and
the for-warding table for node A in the Figure 20.35.