Homework 5
Due  4/29/08

1. Problem 6.16
2. Problem  8.6 of LG&W
3. Problem  8.10  of LG&W
4. Problem  8.29 of LG&W
5. Consider an Ethernet with five nodes A, B, C, D, E having fixed preassigned IP addresses  10.10.1.7, 10.10.1.1, 10.10.1.50, 10.10.1.33 and 10.10.1.31 respectively.  The subnet mask of the network is 255.255.255.0.    The Ethernet (MAC) addresses of the five nodes are A0:30:30:30:30:30, A0:FF:FF:FF:01:10, A0:FE:2F:30:34:43, A0:EE:EE:EE:05:50, and A0:EE:EE:EE:EE:EE   respectively.
   a)      Consider the case where  nodes A-D have been up and running for a while communicating with each other. Assuming the ARP table size to be sufficient to hold ten entries, complete the ARP table at node A.
   b) Node E powers up, and in the process learns its preassigned IP address. A node can always read its own MAC address.  However, no entries are preloaded to the ARP table during power-up.  Node E  attempts to send an IP datagram to node A. Describe the complete sequence of frames exchanged in the process. List all the available information on each frame ( frame type, frame addresses, frame contents – IP, ARP etc, fields in frame contents –IP addresses, etc.  ).
   
6. Consider the network shown below. Assume the cost metric to be the hop count.
   Give the distance vector based routing tables at each node.
   a) Initial tables (i.e., each node knows only the distances to its immediate neighbors)
   b) At the end of following set of  distance vector exchanges:  A->B,   B->C, C->F, D->E
   c) Converged solution after a long series of exchanges.
   
   
   
   
   
   
7. Repeat Problem 6, consideng the following  pre-assigned set of costs. Costs, for example could be  based on the bandwidth of the links, router resources, or ISP charges. 
   Node Pair       Cost
   A-B                   5
   A-D                   2
   B-E                    1
   B-C                   2
   B-F                   2
   C-F                   3
   C-D                   2
   D-E                   1
   
   
   
8. Obtain routing table for node B using link-state algorithm  using cost values specified in problem 8.  Clearly show all steps.
   
   
   
9. The following is a dump of a TCP header in hexadecimal format:
   03320017 00000001 00000000 500207EF 00000000
   a) What is the source port number?
   b) What is the destination port number?
   c) What is the sequence number?
   d) What is the length of the datagram?
   e) What is the  length of the data?
   f) Is the packet directed from a client to server or vice versa?
   g) What is the client process?
   
   
   
10. The following is a dump of a UDP header in hexadecimal format:
    0632 000D 001C D217
    a) What is the source port number?
    b) What is the destination port number?
    e) What is the length of the header?