The Future of the Internet: IPv6

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Revision as of 00:13, 14 April 2008

Introduction

The internet has originall created in .... by .... for sharing information easily between researchers in different parts of the world. It was then adapted as a mean of communication for the United States military. It was not until the early 1990's that the internet as we know it began to emerge. As the internet grew and gained popularity new uses and applications were created to use in conjunction with the initial infastructure. The internet now has ..... billion users and is used everyday for e-mail, e-commerce, communication and media sharing. Even though the original infastucture was not craeted with the intention of supporting these functionalities it has been amazing resiliant in it's uses. However, changes will be nessisary in the near future to support this exponential growth. IPv6 was created to solve many of the current underlying problems.

What is IPv6

IPv6 stands for Internet Protocol version 6. It is the successor to IPv4 which is currently the backbone of the internet infastructure. The Internet Protocol is the dominant network layer protocol on the intertnet. It is used along with other higher level protocols such as TCP and UDP to create connections across the internet to enable inforation sharing. It would make logical sense to assume thay IPv5 would be the successor to IPv4, but IPv5 was created as an internet stream protocol for audio and video. The project was never widely distributed and now we are wait for IPv6 to emerge as the standard.

Why Create IPv6

The IPng (Internet Protocol next generation) was established in 1994 to create a new protocol that would solve some of the issues that plauge IPv4. The main improvments to IPv6 would be an increased address space. IPv4 uses 32-bit addressing scheme which allows for 2^32 unique addresses. Each machine attached to the internet requires a unique IP address, with an increasing number of people and machines using the internet these addresses will eventually be exhausted. IPv6 not only corrects the lack of address space it also enhances routing efficency, increases bandwidth capabilities and provides better security.

IPv6 v.s. IPv4

Address Space

The limited number of availble addresses with IPv4 was the main motivation for creating IPv6. IPv6 operates on a 128-bit addressing scheme instead of a 32-bit scheme. The IPv6 addresses are typically composed of two logical parts: a 64-bit (sub-)network prefix, and a 64-bit host part, which is either automatically generated from the interface's MAC address or assigned sequentially. IPv6 addresses are normally written as eight groups of four hexadecimal digits, where each group is separated by a colon (:). For example, 2001:0db8:85a3:08d3:1319:8a2e:0370:7334 is a valid IPv6 address.

If one or more four-digit group(s) is 0000, the zeros may be omitted and replaced with two colons(::). For example, 2001:0db8:0000:0000:0000:0000:1428:57ab can be shortened to 2001:0db8::1428:57ab. Following this rule, any number of consecutive 0000 groups may be reduced to two colons, as long as there is only one double colon used in an address. Leading zeros in a group can also be omitted (as in ::1 for localhost). Thus, the addresses below are all valid and equivalent:

2001:0db8:0000:0000:0000:0000:1428:57ab
2001:0db8:0000:0000:0000::1428:57ab 2001:0db8:0:0:0:0:1428:57ab 2001:0db8:0:0::1428:57ab 2001:0db8::1428:57ab 2001:db8::1428:57ab

Address Allocation

IPv4 addresses are located by network class. IPv4 classes are rigid and have not been created efficently causing a shortage. The rigid structure also makes assigning addresses to organizaiotn and individuals inefficent creating a need for [1]. IPv6 assignment protocols have not been fully developed but the idea will be to assign every organization, home or entity its own /48 bit prefix. This will allow for a 16 bits for subnetting if nessisary.

Fragmentation

Fragmentation occurs when a packet or datagram is to large for the transfer bandwidth of the phyiscal hardware. The packets are split at the router connected to the connection that does not have enough bandwidth for the packet. Packets are fragmented when nessisary and the path they take to the destination does not matter. IPv6 has fragmenting but it is done at the source instead of at the routers. This is possible because IPv6 determines the route before it sends the packet and fragments accordingly. This creates overhead for the sender but since routers are the bottle neck for trasmitting information accross the internet it is believed that if routers are only responsible for forwarding and not fragmenting this will increse the overall speed of the internet.

Maximum Transfer Unit

The maximun transfer unit is measured in bytes and is 576 for IPv4 and 1280 for IPv6.

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