6.1 INTRODUCTION

The Internet is a world-wide medium which can be conceptualized as a group of hosts interconnected through transmission and switching facilities. Managing the collection of hosts and the transmission and switching facilities which make up the networking resources of the world wide Internet is not homogeneous, it is instead a distributed environment among multiple administrative authorities. Resources under control of one administration within a contiguous segment of network topology form a domain.

Domains which both uses the same resources with other domains are referred to as network service providers. Domains that employ other domain's resources are referred to as network service subscribers. Remember that any domain can perform as a provider and a subscriber at the same time.

6.2 ADDRESS ALLOCATION

There are two requirements with regards to IPv6 unicast address allocation within the Internet.

At present there are several routing domains including corporate and campus networks which are associated with transit networks in only one, or a reduced number of tightly controlled access points.

Addressing solutions that require a great deal of changes or must employ constraints on the current topology don't enter into the picture. In fact, it is the high-end IPv6 address allocation in the Internet, which provide benefits that involve encoding some topological information in IPv6 addresses to extensively decrease routing protocol...