3. Internet Protocol, cont.

• IPv4:

  • uses a 32-bit IP addressing system

  • similar to a town with 4,294,967,296 houses

  • with explosive growth of the Internet, this is no longer enough

  • NAT is required to deal with division between public and private IPv4 addresses.

• IPv6:

  • new addressing system

  • based on 128-bit addressing system

  • vastly enhances the number of addresses available

  • IPv6 addresses in a datagram remain the same throughout a packet's journey across an inter-network.