IPv4 Vs IPv6: All You Need To Know
IPv4 (Internet Protocol version 4) and IPv6 (Internet Protocol version 6) are different versions of the IP (Internet Protocol). Practically, you can think of them as version 1 and 2, for there is no other version of Internet Protocol in operation other than these two.
Let us first understand what the IP is. The IP is the principal communications protocol for transmitting data packets across the network. It carries out this job with the help of IP addresses. Each and every device connected to the internet is assigned a unique IP address.
The packet originating from sender contains the IP address of the receiver, thus, ensuring that it reaches the correct destination. You can find it analogous to our mail system, wherein our mail is sent to the address we have addressed it to.
In the beginning, when the internet was just taking its baby steps in form of ARPANET, IPv4 standard was developed to assign IP addresses. IP addresses assigned under IPv4 are 32-bit numbers, divided into four octets. Each octet being 8-bit in size can accommodate 28 numbers which vary from 0 to 255. Thus, an IP address ranges from 0.0.0.0 to 255.255.255.255 which gives us a total of 232 or about 4.3 billion (109) addresses.
When IPv4 came into existence in 1983, this number was thought to be sufficient enough to never run out. With the access to computers being limited to professionals only, it was difficult to imagine how widespread they would become in coming years. But then came the revolution in internet during the 90s, with computers becoming a household name. And now, with every other person holding a smartphone in his hand these days, the number of internet users has increased leaps and bounds.
This increase has forced the IETF to look for an alternate solution as there are not enough IP addresses available to assign to all the users. For instance, in 2016, approximately 6.4 billion devices were connected to the internet, which is more than the total IP addresses available.
IPv6 was developed in 1998 by IETF (Internet Engineering Task Force) while keeping in mind the problems which IPv4 may face in future. The numbers of users were increasing rapidly during that period and those 4.3 billion addresses were going to exhaust soon enough. Although, being developed in the mid-90s it started gaining popularity much later in recent years only.
IPv6 uses 128-bit addresses consisting of eight groups, with each group being 16 bits or 2 bytes in size. Each group is made up of four hexadecimal digits and can have numbers from 0 to 216-1. This makes a total of 2128 i.e. 340 undecillion (1036) addresses available to us. Whew! Certainly, we are never going to exhaust those many addresses in any foreseeable future.
IPv6 is a straightforward solution to the problem of “address exhaustion” posed by the IPv4. In addition to this, IPv6 allows hierarchical routing infrastructure i.e. more subnets can be created by corporations for their internal usage, allows multicasting and many more improvements over IPv4.
But the biggest obstacle in the process of IPv6 adoption is the fact that IPv6 isn’t backward compatible with IPv4. This means that an IPv6 server is needed for an IPv6 address and an IPv4 server is needed for an IPv4 address. There is no mechanism available for the transition between these two addresses.
To support both you need to have both IPv4 and IPv6 addresses assigned to your system or network. This means we have to upgrade our older networks to make it IPv6 compatible, which would prove to be a costly affair.
Several mechanisms are being designed to facilitate IPv6 adoption among different websites. These days, the latest versions of major operating systems come with an inbuilt support for IPv6. But this transition will take time as it is not easy to dismantle a more than 3 decades old system, which carries almost 99% of the total internet traffic and replace it with a new one.