Answer the following:

a what is a whois database?

b Use various whois databases on the Internet to obtain the names of two DNS servers. Indicate which whois database you used.

c Use nslookup on your local host to send DNS queries to three DNS servers: your local DNS server and the two other DNS servers you found in part (b). Try querying for Type A, NS and MX reports. Summarize your findings.

d Use nslookup to find a web server that has multiple IP addresses. Does the Web server of Columbia University have multiple IP addresses?

Note: Some DNS servers will only respond to DNS requests for their domain. For example, you can find googles DNS server but if you ask googles DNS server for cnn.com address, it may not work. Why may this be so? If you try this, be sure to explain. Otherwise, avoid this by only making requests to DNS servers for their authoritative address.