Homework #4 Solution

This homework contains both technical and business­related DNS problems, for the total of 100 points. Reading assignment: Chapter 5 (and references).

1. (5 points) Find out the exact number of all top domain names. Make sure you put a date and time of your finding. (Hint: use the information given at the lecture to locate the list of names at IANA.)

2. (5 points) Experiment with www.i      (http://www.i) nternic.net  and http://whois.domaintools.com     (http://whois.domaintools.com/) ) and

1. Find the information about the stevens.edu domain as well as the domain of some other school (for instance, the school you had studied at before you came to Stevens). Who are the administrative contacts for the domains listed there?

2. Now, what happens when you try to find the administrative contact for the .xxx domain? Explain what you have found.

3. (5 points) Look up www.cs.stevens.edu at http://network­tools.com/nslook/     (http://network­tools.com/nslook/)  (or any other DNS lookup tool you decide to use), copy the response, and explain all the entries in the response.

 

Then use the returned CNAME entry to find the exact IP address. (Now, just for fun, do the reverse DNS lookup using the services of the

http://dnsquery.org     (http://dnsquery.org/) and find the geographic location of the host!) Does Stevens specify IPV6 addresses to any of its hosts? Does Google?

1. (5 points) Find your PC’s IP address (preferably at home, if you have an Internet connection there.)  Can you find your domain with the reverse look

up? If you can, what is the domain name? If you cannot, explain why.

2. (10 points) Research the responsibilities and structure of IANA (www.iana.com      (http://www.iana.com) ) and ICANN (www.icann.com (http://www.icann.com) ). What are the differences in responsibilities between these two organizations? Search the web for the information and then describe the controversy in ICANN concerning Whois?

3. (50 points) The Spamhaus attack

1. (5 points) Read https://www.isc.org/blogs/is­your­open­dns­resolver­part­of­a­criminal­conspiracy­2/      (https://www.isc.org/blogs/is­your­ open­dns­resolver­part­of­a­criminal­conspiracy­2/) . Describe (in no more than a couple of paragraphs) the Spamhaus attack and explain the dangers of open recursive resolvers.

2. (45 points) Find out (you will need to search the Web and sort a lot of information out!) how cloud services were used to mitigate this attack.

4. (10 points) Study the Amazon Route 53 service and answer the following questions

1. What does Route 53 do?

2. Why is it called Route 53?

3. What other Amazon services is it designed to work with (please explain how it happens with one or two examples)?

4. What is the difference between the domain name and hosted zone?

5. Does Route 53 have a default for the Time­to­live (TTL) value?

6. What is the pricing of the service?

5. (10 points) Take a look at the Cloud Floor DNS  (https://www.mtgsy.net/      (https://www.mtgsy.net/) )

 

The company advertises the Native Cloud Discovery service. What does it do? (Just research your answer and explain how you understand it.) Does Route

53 provide a similar service?