Evolve or die is true in nature and in the Internet. As the demands of the Internet and intranets grow, old technologies and techniques show their faults and new ones evolve. Evolutions such as POP3 email clients giving way to IMPAP 4 clients, but most fundamental evolution underway has to do with IP itself.

The old standards for IP packets, called IP version 4, or IPv4, have been eclipsed by a new standard, originally referred to as IP Next Generation, or IPNG, and now recognized as the sixth version of IP, or IPv6. IPv6 is examined here covering also the very important concept of quality of service.

The primary motivation for developing of IPv6 was to escape the limits of IP addressing in IPv4. In IPv4, each IP address consists of 32 bits arranged in 4 bytes. This allows for four 1-byte numbers between 0 and 255 separated by a period. According to the class of network, one two or three bytes can identify the network or one, two or three byte can provide the identification for the specific computer with the network.

When this 32-bit addressing arrangement was developed, no one seriously considered that growth and inefficiency would cause us practically to run out of numeric Ip addresses.

The solution that appealed to the technically minded folks running the Internet Engineering Task Force (IETF) was to increase the size of the IP address space. Lengthening the address by 1 bit doubles the number of value it can have. IPv6 has 128 bit addressing and allow for over 4 billion billion times the address space of IPv4.

Many of the human inefficiencies of IP address assignment that plague IP4 will still exist for IP6, and people will still waste groups of addresses, but the system ensure room for plenty of human inefficiencies and still provide addressing for billions of nodes.


But who needs it ?

The rub in this plan is the concept of network address translation (NAT) since individual LANS don\'t need to have a registered IP addressing plan inside the LAN, the pressure for registered IP address has abated.

Furthermore with the need to replace all the addressing method of all machines and servers presently on the Internet and within networks pose a huge problem since there are clusters of machines that are the core of internetworking that are still running on the old method. Having to replace them will require alot resources in term of time and money.

The only real disadvantages of NAT are the possibility of delays within the device doing the translating which has been minimize with newer and better equipment surfacing each year. The other negative point of NAT is that some application such as TRACE ROUTE doesn\'t work with all translation schemes, plus the requirement of mapping ports to its destination locations within the LAN if there are servers running.

IP6 will eventually be implement for a variety of reasons beyond addressing as adopting of this protocol also carries some interesting services across the Intenet and your intranet. But the push for it has been slow so far.

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