A client seeks to resolve the following URL wwwcsuwaterlooca

A client seeks to resolve the following URL:

www.cs.uwaterloo.ca

Assume that each component of the name is a zone, resolving from right to left.

A)Describe how iterative name resolution occurs in DNS between (i) the client\'s local name server, and (ii) each of the remaining name servers involved in the resolution for each portion of the name. Assume that there is no helpful cached information at any step.

In providing your answer, assume that each label in the name is resolved by a unique name server. In your answer, I don\'t need the fine details of message contents; instead, I want you to identify the source (a name server) and destination (a name server) of each message that is passed along with the basic information about what has been resolved and what has not.

B)Briefly (at most 5 sentences) explain the difference between authoritative and non-authoritative responses in DNS.

C) What are the top-level domain in the two URLs used in this question?

Solution

A) DNS using iterative name resolution perform resolution using the information within its own look-up table. It doesn\'t query other name server for information. When a client request is sent it searches local databased and if it has value it will reply. If not it will respond with host not found message.

B) An authoritative results come from a nameserver that is considered authoritative for the domain which is returning an elements for( one of the nameservers in the list for the domain you did a lookup on).

A non-authoritative answer comes from anywhere else (a nameserver not in the list for the domain you did a lookup on)

C.) Domain name :- .ca etc