Motivation: No more IPv4 addresses available as of February 2011.
IPv4 Address Space 2^32 ~ 4.3 billion -- not enough to accomodate all routable networks in the world since beginning of 2011.
IPv6 Address Space 2^128. Any square meter on earth can be assigned a routable IP address in IPv6 space.
Types of IPv6 Addresses:
Unicast addresses: destination at a single interface
Multicast addresses: destination at multiple interfaces with different IP addresses
Anycast addresses: destination at multiple interfaces with the same IP address (used on routers).
IPv6 Address Notation:
Network Notation in IPv6: