Computer Science 881
                            Quiz 1             Name_______________________

1. The networking subsystem in Linux is implemented using has a
   layered architecture that consists of the following layers:
   af_inet, dev, device driver, ethernet, ip, socket, and transport
   layers.  Provide a diagram of the layers stacked in their proper
   order.  (You may use a two column format to save space and
   preserve legibility).















2. What is the name of the structure used to convey the receive entry
   point of a transport protocol to the IP layer?




3. ARP neighbor structures represent:

   a. A single entry in the linux     b. Each host with which this host has
      routing table                      been in recent communication.

   c. Each host that is reachable
      in a single transmission and
      which this host has been in
      recent communication

4. A single entry in the Linux routing table best corresponds to

   a. An element of type              b. An element of type struct
      struct rtable                      dstentry

   b. An element of type
      struct fib_node


5. Each host with which this host has been in recent communication is
   represented by:

   a. An element of type              b. An element of type struct
      struct rtable                      neighbour

   b. An element of type
      struct fib_node

6. The struct packet_type is used in binding

   a. network layer to transport      b. transport to socket

   c. af_inet to transport            d. network to dev


7. The struct proto is used in binding

   a. network layer to af_inet        b. transport to af_inet

   c. network to dev                  d. af_inet to socket


8. The struct proto_ops is used in binding

   a. network layer to af_inet        b. transport to af_inet

   c. network to dev                  d. af_inet to socket

9. When a new fib_node is to be added, precisely what determines
   the element in the fn_zones[] array to which it is assigned.






10. When a packet is to be routed, the routing algorithm looks

    a. First in the FIB and if that    b. First in the route cache
       fails in the route cache           and if that fails in the FIB

    c. Randomly chooses between the
       two.

11. During a FIB lookup

    a. Only one fn_zone[] will ever    b. It may be necessary to
       need to be searched.               search several zones but
                                          the search might require
                                          only one zone.

    c. ALL zones must always be
       searched.

12. During a route cache lookup

    a. Only one rt_hash_bucket[] will  b. It may be necessary to search
       ever need bo be searched           several buckets or one may
                                          suffice

    c. All buckets must always be
       searched


13. If one is to implement a completely new protocol stack (e.g. PF_SNA
    for IBM's SNA), which of the following structures would have to be
    provided using the standard Linux structures named below and which
    could use private structures or be omitted completely depending upon
    the architecture of your new stack.

    ____ a. struct net_proto_family

    ____ b. struct proto_ops

    ____ c. struct proto

14. Suppose a system has 256MB of real memory. How many entries will
    the routing cache hash table contain?