Computer  Science 481/681
                        Quiz 6  -         Name ________________________

1. The OSPF routing protocol is classified as:

   a. vector distance                    b. link state

   c. nearest neighbor                   d. ink stain

2. Each OSPF routing update propogates

   a. only as far as directly            b. Throughout the entire
      attached neighbors.                   internet

   c. Among all the OSPF routers         d. Among all the Exterior
      within an AS or subarea.              Gateways of an AS.

3. In the SPF computation,  each time a node on the tree is made
   permanent it is necessary to (possibly) update the shortest path
   distances from:

   a. every temporary or permanent       b. every permanent node to every
      node to every other node.             other node.

   c. only the newly permanent node
      to every other node.

4. A packet is routed through an OSPF based AS:

   a. Using a source route computed    b. Using a single routing
      by the source router.               tree with the original
                                          source at the root.

   c. Using multiple routing trees
      with each router at the root
      of its own tree.

5. OSPF routing exchanges are transported as:

   a. IP header options                b. ICMP messages

   c. IP datagrams using their         d. E-mail datagrams.
      own protocol number.

The next few question relate to Paxson's Paper

6. The basic mechanism used by Paxson to detect routing pathologies
   was

   a. traceroute                       b. ping

   c. TCP connect requests             d. e-mail messages

7. The study involved transmission tests

   a. Exclusively from Paxon's lbl     b. From a number of interational
      site to a number of                 sites exclusively to lbl.
      international sites

   c. Among a collection of international
      source and destination sites.

8. The time duration of the most persistent routing loops was
   on the order of

   a. milliseconds                     b. minutes

   c. hours                            d. weeks

9. The location of routing loops was:

   a. always confined to within a      b. always involved multiple AS's
      single AS indicating the            indicating failure of BGP's
      presence of inconsistent OSPF       loop supression.
      trees.

   c. Equally distributed among
      intra-AS and inter-AS loops


10. Consider the network shown on the board

   a. Draw the directed graph representation of the topological database
      in the form used in the OSPF RFC (distributed in class).


















  b. Draw the routing tree for RT 6