What’s IPv4 and why do you need to move on to IPv6?

Today is the official launch of Internet Protocol Version 6. So on this occasion I am writing about few things which all IT folks should know about Internet Protocol and different versions of it.

Internet Protocol or IP addresses are used to identify a device which is connected to the Internet. All devices on the Internet are addressed using a protocol set by Internet Assigned Numbers Authority (IANA http://www.iana.org/). This organization is responsible for all IP address pools. IANA distributes large blocks of IP addresses to Regional Internet Registry (RIR http://en.wikipedia.org/wiki/Regional_Internet_registry) which intern distributes them to vendors. Most of the Internet is currently addressed with Internet Protocol Version 4 (IPv4).

IPv4 format has four numbers with three digits each which are separated by dot. For example: 192.168.10.1

This allows IPv4 to have 4,294,967,296 individual IP addresses. According to IANA we ran out of IP addresses using IPv4 in Feb 2011. What this means is you can not get on to the Internet using a new device using IPv4. However individual RIR still have some pools of IPs which they are distributing. Asian RIR has already run out of IP addresses under IPv4.

So IANA has come up with a new version of called IPv6 which is successor of IPv4. Both versions will be used for many years since it is realistically impossible to replace all devices which have IPv4 address. However moving on most of the devices will be using IPv6.

IPv6 is works same as IPv4 by providing unique number for each device to communicate over the Internet. IPv6 uses 128 bit addresses as opposite to IPv4 which uses 32-bit addresses. So IPv6 has significantly large number of unique combinations. IPv6 IP address has eight groups with each group having 4 alphanumeric values separated by colons. For example:

2012:ABC1:123E:6786:ADDC:1234:ABCD:88YY

Maximum number of IPs which IPv6 can hold is 340,282,366,920,938,463,463,374,607,431,768,211,456 which I think is 340 trillion trillion trillion.

IPv5 also exists as Internet Streaming Protocol used for streaming audio, videos over the Internet. It was never widely distributed and now is called ST2.

What if your organization does not move to IPv6?

It means you are stuck with whatever IPs you have with IPv4. You will have to reuse those IPs as you grow. Also as world moves on to IPv6 they wont be able to connect directly to your website or application if you are still using IPv4.