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What’s the difference between IPv4 and IPv6?

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What's the difference between IPV4 and IPV6?

The number of users connected to the internet has gone up drastically since its invention in 1983. The web uses an IP address to identify each device connected to it uniquely. The internet started as ARPANET and had about 16 million users in 1995. This number has grown up significantly due to easy with which one can access the internet, especially since after smartphones were launched. In addition to this, each user has multiple devices causing more traffic over the internet.

IP (Internet Protocol) is a protocol which assigns a numerical address to each device that connects to the internet. As an analogy, it is like your houses address and helps to identify each device connected to the internet just like your postal address. Without this protocol, there would be no way to recognise each device.

IPv4 (Internet Protocol version 4) was defined in 1981 and could address a total of 4.2 billion users. The internet currently has a total of 4.5 billion users. Due to this enormous number of devices that connect to the internet, there was a need for a new internet protocol. This is how IPv6 was born. IPv6 was defined in 1997 and became an internet standard in 2017. IPv6 could address a total of 340 undecillion addresses — 340 billion billion billion billion. Looking at this mind bobbling number one can say there will be no shortage of IP addresses.

Also read: What is DNS and how does it work

IPv4 and IPv6 compared

There are several differences between IPv4 and IPv6, and we will be going over a few of the key ones below.

  • IPv4 uses a 32-Bit IP address whereas IPv6 is a 128-Bit IP address.
  • IPv4 is an address representation in decimal format, whereas IPv6 is an Address Representation in hexadecimal.
  • A dot separates IPv4 binary bits whereas a colon separates IPv6 binary bits
  • IPv4 has 12 header fields whereas IPv6 offers eight headers.
  • IPv4 provides checksum correction while IPv6 doesn’t have a checksum.
  • IPv4 is VLSM (Virtual Length Subnet Mask) compatible whereas IPv6 doesn’t have VLSM.
  • IPv4 uses ARP (Address Resolution Protocol) to map MAC address whereas IPv6 uses NDP (Neighbour Discovery Protocol).
  • While the fragmentation is executed by the sender and forwarding routers in case of IPv4, the sender is solely responsible for this activity in the case of IPv6.
  • IPv4 does not have encryption and authentication, whereas IPv6 provides both encryption and authentication.
  • End connection integrity is unachievable in IPv4, whereas IPv6  end connection integrity is achievable.

Also read: Internet Safety: Should you trust HTTPS? HTTP vs HTTPS


Nischay Khanna

A tech enthusiast, driven by curiosity. A bibliophile who loves to travel. An Engineering graduate who loves to code and write about new technologies. Can't sustain without coffee. You can contact Nischay via email: