How many layers are defined for the ISO-OSI model?
   The ISO-OSi model has seven layers.

     Physical
     Data link
     Network 
     Transport
     Session
     Presentation 
     Application

  
  * Assume that most remaining questions follow the TCP/IP model, if it
    applies, rather than the ISO-OSI model.

 How many layers are defined for the TCP/IP model?
   The TCP/IP model is usually represented as a 4 layer model.

 Name them.

   Link (data link)
   Internet
   Transport
   Application 


 Which layer deals with the mac address?
   
   The media access control (mac) is delt with at the link layer.

 What is the purpose of mac#? 

   It uniquely identifies the local network card on the local network.

 What are the major parts of the mac#?
   
    The mac is broken into 2 parts :
      Organizationally Unique Identifier - OUI, an id assigned to a 
        specific card manufacturer.

      Network Interface Controller Specific - NIC, unique identifer for
        the card.

 What size of each part of the mac# on ethernet cards?

   Each half of the MAC is 3 octets (3 bytes) in size for a total 
     of 6 bytes.

 Which layer makes use of ip number?

   Internet layer.

 Which layer makes use of the port number?

   Tranport layer.

 What field is used to count the hops across the internet to guard against
  lost packets (2 versions exist)?

    TTL (Time to live) for IPv4 uses both number of hops across internet 
      and actual time packet existed to guard against a lost packet.

    Hop count for IPv6 just counts hops across interet. 

 Which protocol layer is it used in?

    Internet layer.

 Match the specific field to the specific version of the protocol. 

    TTL (Time to live) used by IPv4 

    Hop count used by IPv6

 Where does the url reside?

   The url is specified in the application layer and translated to an ip
     number by the DNS service.

 What does TCP stand for?

   Transmission Control Protocol

 What does IP stand for?

   Internet Protocol
 
 What does ICMP stand for?

   Internet Control Message Protocol

 What does UDP stand for?
 
   User Data Packet.

 Which protocol uses a connection-oriented protocol?
   
   TCP

 Which protocol uses a stateless connection?

   UDP and ICMP (connectionless and stateless refer to same property)

 Which protocol initiates a connection by sending syn packet, waits
  for a and ack/syn packet and finalizes the initiation with a ack packet.

  TCP (this is the protocol for establishing a 'connection')

 How many bits are an IPv4 address?

   32 bits ( 4 - octet id)
    
 How many bits are an IPv6 address?

   128 bits ( 64 bit domain identfier and 64 host identifier.

 Which generic protcol allows multiple users to share access to a local network
   with no restrictions on access order other than not talking if network is 
   busy? 
 
   CSMA/CD - carrier sense multiple access / collision detection

 What specific technology it is implemented on?

   Ethernet

 Which technology uses a round-robin permission scheme to guarentee each user
   on the network is guarenteed a chance to communicate and implements it at
   the physical layout layer?

   Token ring uses an actual physical ring to implement a "round-robin" 
     topology to pass a token from host to host in a time controlled manor to
     guarentee each device a time to use network.
   
 Which technology uses a round-robin permission scheme to guarentee each user
   on the network is guarenteed a chance to communicate, but can be implemented
   on iinear or other non-ring topologies?
 
   Arcnet used a generated sequencial id to create virtual ring on top of a
     variety of non-ring topologies. The opportunity (time) to use the network 
     was detemined by the order of the ids but every host was guarenteed a 
     time to use the network.
     determined by 

 What other technology uses physical topology of linear bus, star, or tree?

   Ethernet
  
 Which protocol supports class addresses?

   IPv4

 Which protocol is considered connectionless but is still responsible for
   end to end delivery of information?    

   UDP, ICMP  
 
 Which protocol converts between ip addresses and URLs (internet names)?

   DNS (Domain Name services)

 Which protocol converts between mac# and ip number?

   dynamic host configuration protocol
 
   DHCP  (bootp and arp/rarp were eariler implementions of mac <-> ip)

 Which port is reserved for ssh servers to listen on?

   Port 22

 Which port does the DNS server listent on?

   Port 53

 What organization is responsible for managing the Domain Name System?

   ICANN  International Corporation of Assigned Names and Numbers.

 What are the very top level servers for the Domain Name System called?

   Root servers.

 Which port it the legacy non-secure port used for telnet?

   Port 23

 Which protocol/utility uses a pair of ports, one for control and one for
   data?
 
   ftp 20,21