IPv6 is the succession to IPv4, a publicly used Internet Protocol, and is designed to meet the requirements of Internet expansion. While IPv4 is still the most widely used, the Internet Engineering Task Force is advising all to use IPv6 because of the foreseeable exhaustion of IPv4. Colocation America offers a vastly larger address space which derives from their usage of a 128-bit address. This expansion gives the flexibility that allocating address and routing traffic needs, as well as eliminates the need for NAT [network address translation].
There are several new features which make IPv6 smoother and an improvement over IPv4. The simplification of stateless address configuration and network renumbering speeds along the process of switching Internet connectivity providers. Contrary to popular belief, IPv6 is not completely different than IPv4, it is simply slightly more advanced with the goal of solving the problems it left behind. The main differences between the two versions occur in the following areas: addressing and routing, security, network address translation, administrative workload and support for mobile devices. However the most important feature that IPv6 has is a set of possible migration and transition plans from IPv4.
The Internet Protocol [IP] is one of the pillars in support of the Internet which has been around for almost 20 years. It originated as a concise set of 45 pages in RFC 791 and acts as the network-layer protocol for the Internet. In 1991 the IETF determined that the IPv4 had outgrown its design and moved to develop the next thing. After much research, the IETF released a clear direction and IPv6 started to be formed in 1994. It is now described in the Internet standard document RFC 2460, published in December 1998. As of 1994, over 30 IPv6 RFCs have been published.
The most impactful change from IPv4 to IPv6 is the actual address. IPv4 had a 32 bit long [4 bytes] address, which is composed of a network and host portions. With IPv6, address are now 128 bits long [16 bytes], typically the host portion of this address will be derived from a MAC address or other interface identifier.
In text format, an IPv4 address is as follows:
Each n is a decimal digit
In text format, an IPv6 address is as follows:
Each x is a hexadecimal digit
A double colon ( : : ) can be used when the address is in text form to designate any number of 0 bits.
IPv4 addresses were originally allocated by network class and as space is depleted, smaller allocations using CIDR (Classless Inter-Domain Routing) are made. IPv6 is still in early stages when it comes to allocations. The IETF (Internet Engineering Task Force) recommends that every home, organization and/or entity be allocated a /48 subnet prefix length. This leaves bits for the organization to subnet.