Computer  Science 481/681
                        Quiz 8  -         Name ________________________

1. To send a UDP datagram a program must first create a socket of
   type:

   a. SOCK_RAW                           b. SOCK_UDP

   c. SOCK_STREAM                        d. SOCK_DGRAM

2. The recvfrom() system call (like sendto) contains a pointer
   to struct sockaddr_in.  This structure is used to specify

   a. The local address to which         b. Contains the IP and Port
      the recipient is willing              address of the sender at
      to accept datagrams.                  when the receive completes

   c. Both a. and b.                     d. Neither a. or b.

3. The type of service provided by UDP is best described as

   a. Connection oriented and            b. Connection less and
      reliable                              reliable

   c. Connection oriented and            d. Connection less and
      unreliable                            unreliable

4. Which of the following "offenses" are most likely to be encountered
   by users of UDP

   a. Delivery of duplicate copies       b. Discarding and thus "loss"
      of a single packet.                   a complete packet.

   c. Loss of part of a packet.          d. None of the above are ever
                                            encountered using UDP

6. The maximum size of a UDP datagram that can be transmitted with
   sendto() (i.e. sendto will actually send it not give you back
   an immediate -1 return code)


   a. is always 64K bytes.               b. Varies from system to system
                                            but is generally larger than
                                            8K bytes

   c. is always 65507 bytes.             d. Is 256 bytes.

7. Setting the IP address field of the sockaddr_in field specified
   in the bind system call to 0

   a. makes the socket not usable        b. specifies the receivers
      for receiving any data.               willingness to accept datagrams
                                            from any remote IP address.

   c. specifies the receivers
      willingness to accept datagrams
      directed to any local IP address.


8. Which of the following network api system calls can be used to
   specify that you wish to receive ONLY those udp packets that arrive
   from a specific remote IP address?

   a. bind                              b. select

   c. connect                           d. reject

9. Assuming that DF is not set. Fragmentation works the following
   way in IPV4:

   a. A packet must be broken down      b. A packet will be fragmented
      into MTU size frags by the source    by the router owning the link
      host and will be reassembled at      whose MTU is too small and
      the destination.                     will be reassembled by the
                                           next router that can handle the


   c. A packet will be fragmented       d. A packet must be broken down
      by the router owning the link        into MTU size units by the
      whose MTU is too small but not       originating host but will
      reassembled until it reaches the     be reassembled as soon as it
      destination.                         passes the bottleneck router.

10. The ARP pathology example in the book shows that a UDP datagram
    transmission from a host on an ethernet will fail:

    a. Any time the packet to be sent   b. Whenever the next hop hardware
       is larger than Ethernets MTU        address is not in the ARP cache.

    c. Either a. or b. is true.         d. both a. and b. are true.

11. In the same example it was also noted that an ICMP reassembly
    timeout was not returned. The impact of this on the application is:

    a. the application will hang        b. the "sendto" function will
       in "sendto."                        return a misleading error
                                           code.

    c. none at all. From the apps
       perspective the situation will
       be exactly as if the ICMP message
       had been sent.