CIS 656_105, Homework for Oct 31, 2001. Read Comer I pp 197 - 207 (Ch 12). If you have not done so yet: read man telnet . (Do not hand in). Recommended reading (not compulsory): RFC 1122, sections 3.3.2 and 3.3.3. How does this relate to the homework for Oct 24, 2001? (do not hand in). (1) Use traceroute to show that the computers afs1 , ... , afs36 in Room GITC2305 are all on the same network. (At least: the few I tried were all on the same network). Hand in a FEW runs and explain how this shows they are on the same network. Help: You do not need to be in room GITC2305 to do this. You can telnet in to any of those computers and from there traceroute to any of the others. From outside the domain ``njit.edu'' you must use the full name (alias). For example afs1.njit.edu . Use ping with a range of data sizes to estimate the bandwidth of the LAN the computers in GITC 2305 use. Hand in enough of a copy of the runs (and not too much!) that it is clear what you did. Explain the procedure you use. How reliable do you think the result is? What range of data sizes is best? explain. How many different data sizes should you use? explain. Given one specific data size, how do you estimate the RTT for that datasize? Do you use min RTT? max RTT? mean RTT? Something else? Motivate your answer. Use nslookup to find the real name and address of afs15. Hand in. --- (2) The maximum packet size a computer can receive (re-asemble) is called its EMTU-R. Find a computer across an ocean where that EMTU-R is considerably less than (2^(16)-1). Call that computer FC (Favorite Computer). Do traceroute to that computer. Find the EMTU-R values of a few of the intermediate routers. If you are ``lucky'', at least one of these routers has an EMTU-R less than that of computer FC. If you found this: How do you explain this? If you did not find this: How would you explain this if you found it? Hand in enough copies of runs to make clear what you did, further as little as possible. Make your explanations short and concise. Hand in Oct 31.