Every computer/internet user has heard of a term IP address which is a short form for Internet Protocol. Every device needs an IP address to communicate with other devices over internet. IP addresses are unique identification labels assigned to devices connected over internet. We are quite familiar with IPv4 or Internet Protocol Version 4 addressing system which provides a 32-bit (4 bytes) IP addresses for example 10:20:56:78 is a IPv4 address. With IPv4, around 4.29 billion unique addresses could be generated (2³²) or in other words 4.29 billion devices could be connected to internet. Over 4 billion IP addresses were more than enough when IPv4 first came into service in 1983 but in the current era with the rapid growth of internet usage, mushrooming of internet devices and technologies like Internet of Things (IoT) is leading to the faster exhaustion of IPv4 address space. The problem was long anticipated by Internet Engineering Task Force (IETF) who developed the most recent version of Internet Protocol - IPv6 which will eventually replace IPv4. IPv6 uses 128 bits (16 bytes) for IP address, for example: 2002:0DB8:0233:AB00: 0234:5678:8901:ABCD is a IPv6 address. With this new addressing it is possible to connect 340 trillion trillion trillion devices that seems to be enough for a long, long time. Figure below shows the breakdown of 128-bit IPv6 address

Image Source - Reference 1

Nowadays every person is having many gadgets which need IP addresses for communication over internet. As the Internet usage continues to grow, we're running out of IPv4 addresses, only IPv6 addresses can accommodate this growth. Insufficient number of IP addresses would have caused the large number of internet users to shut down their computers. But luckily, the problem was noted early, long before the numbers started to run too low.

IPv6 benefits everyone either directly or indirectly. In addition to providing large capacity of IP addresses, IPv6 comes with various added benefits. Compared to IPv4, IPv6 has a much simpler header format, which provides simpler and more efficient routing. Not to forget, IPv6 provides automatic configuration of host devices, has its own built-in authentication and privacy support, mobility of hosts to roam different geographical areas while maintaining connection with the same IP address, direct connectivity between all hosts on the Internet and security for standard internet traffic. Soon IPv6 will be the only option for connecting new devices to internet.

We can expect IPv6 adoption to continue to rise sharply. Deployment of IPv6 started in 2000 but the adoption was quite slow, until recently, due to the compatibility issues. Changes were required in both software and networking devices to make them compatible with both IPv4 and IPv6 as for a long time both protocols will have to coexist. How fast the deployment of IPv6 is progressing is illustrated roughly by the Google IPv6 Adoption Page as shown below. Since 2013 the usage of IPv6 has seen an exponential growth but it will take many more years for the full replacement of IPv4.

Image Source - Reference 2

According to Google, the percentage of users that access its website over IPv6 was mere 10 percent in January 2016 and but it surpassed 20 percent for the first time in July 2017. Over 20,000 websites are now using IPv6 including Google, Facebook, YAHOO, WIKIPEDIA, and YouTube.

By - Yadvir Kaur, Assistant Professor, CSE Dept. Chitkara University, HP

References:-

1. https://orbitalunderground.com/ipv6-information/
2. https://arstechnica.com/information-technology/2016/01/ipv6-celebrates-its-20th-birthday-by-reaching-10-percent-deployment/