Computer  Science 826
                         Quiz C           Name _______________________

1. Two types of query that are possible in DNS are "recursive"
   and "iterative". Describe how each approach works. USE A DIAGRAM
   to illustrate your discussion.

   a. Iterative -









   b. Recursive -








2. We went through an example program that illustrated a mechanism for
   accessing the DNS through the resolver library.  To accomplish a
   "gethostbyname" function using the resolver library requires

   a. A single call that builds the       b. Three calls: one to build the
      query, sends it and receives           query, one to send it and one
      the answer.                            to receive the answer

   c. Two calls: one that builds and      d. Two calls: one that builds the
      sends the query and a second that      query and another that sends
      receives the answer.                   it and receives the answer.


3. When an application calls the resolver library, the resolver
   typically transmits the query:

   a. directly to one of the              b. to a local nameserver
      root name servers.

   c. to the nameserver that owns the
      name to be resolved.


4. In most implementations of DNS, local caching of names is done:

   a. By the resolver.                    b. By the local nameserver

   c. By both the resolver
      and the local nameserver            d. Not at all.



5. What type of RR's would be expected from a non-recursive type "A"
   query to a Root NS for www.info.billgates.ee (Hint: possible
   answers include: "answers" "authority" "additional info")




6. What type of RR's would be expected from a non-recursive type "A"
   query to the nameserver that has authority for zone info.billgates.ee
   for the name www.info.billgates.ee.





7. Characterize "permissive" and "non-permissive" filter rules:


   ___ a. permissive             1. Safe and unobtrusive

                                 2. Safe and obtrusive
   ___ b. non-permissive
                                 3. Unsafe and unobtrusive

                                 4. Unsafe and obtrusive

8. In addition to providing some measure of intrusion protection
   what other major benefit does use of a NAT gateway provide?





9. In outgoing packet the NAT gateway typically translates:

   a. Source IP                 b. Source Port

   c. Dest IP                   d. Dest Port

   e.  a. and b.                f. c. and d.

   g. all of the above


10. In incoming packet the NAT gateway typically translates:

   a. Source IP                 b. Source Port

   c. Dest IP                   d. Dest Port

   e.  a. and b.                f. c. and d.

   g. all of the above

11. In incoming packet the ONE item that can suffice as
    a table lookup key is:

   a. Source IP                 b. Source Port

   c. Dest IP                   d. Dest Port