Homework 2

Due October 16, 2009

You need to turn in Problems 1 and 2. No need to turn in the rest.

Problem 1. nslookup is a useful tool for querying DNS servers. This tool is available (as a command line) on a variety of operating systems  including Linux, Windows or Mac. Familiarize yourself with using nslookup (use command line help or lookup manuals on the web). Note that turning debug on often provides more information. Take a special note of the different DNS query types and how to change the DNS server. Use nslookup to answer the following questions. You can use any machine on the Internet, including your personal laptops.

1.       What is the canonical name of the webserver: www.wings.cs.sunysb.edu? What is the IP address (or, addresses, if the name maps to multiple IP addresses)? How long is the DNS timeout?

2.       Repeat the same question for the webserver: www.cnn.com? Do you find any difference in the nature of these two servers? Why do you think there are such differences?

3.       What is the name and IP address of the name server for the domain: wings.cs.sunysb.edu?

4.       Who handles the mail for the domain: wings.cs.sunysb.edu?

Problem 2. Solve Problem P19 from Chapter 2. You can still use nslookup. It is not necessary to use dig.

Problem Set: Solve the following problems from Chapter 2: P7, P8, P9, P10. No need to turn these in. They will not be graded. But solutions will be posted after the deadline that will be useful for future quizzes and exams.