When we ask clients for their IP address and they look it up, they sometimes get confused and ask us to clarify the differences between IPv4 & IPv6. So, you know what an Internet Protocol Address (IP) is. But do you know that there are two versions of what is known as an IP address? Before we clear that up, we think a little background should help.

About three decades ago, what is now referred to as an IP was first used privately by the US Department of Defense before it was made public. As the internet expanded and more people started to connect to it, there was even more demand for IP addresses to be assigned to devices connected to a network. This earlier set of IP addresses assigned belonged to the IPv4, which means Internet Protocol Version 4. Over time, due to excessive demand, we started running out of addresses for the earlier version of IP. Because everyone connected to a network must get assigned an IP, there was a need to provide an alternative solution to ensure a continuous supply of IPs; everybody who connects to the internet via any network gets assigned an IP. This brought about the second version of the Internet Protocol, IPv6 – Internet Protocol version 6.

What is IPv4?

The fourth version of IP uses a 32-bit system. The IPv4 address is made up of four numbers. These numbers are separated with a single dot containing between one to three digits. These four numbers must not exceed 255 and should not be less than 0. If they are, the IP becomes invalid. For example, 182.25.12.111 is a valid IPv4 address because all four numbers fall within 0 and 255. But 251.25.267.288 is not a valid IPv4 address. Version 4 IP powers a large percentage of Internet traffic. While it was not thought possible at the onset that the IPv4 would run out of addresses, it has. And this created an urgent need for another version to be developed. The IPv4 can either be public or private. A private IPv4 means that your IP is restricted to a private network and cannot be found on the broader internet. A public IPv4 means you can be found on the internet.

What is IPv6?

IPv6 was developed as a solution to the limitations of IPv4 : there were just not enough addresses on it to be assigned to every internet user. It is known as Internet Protocol version 6. This version of IP is quite new as it was developed in 1998. Unlike IPv4, IPv6 operates a 128-bit system. It is made up of eight parts which are separated by a colon . Each of these eight parts contains four unique digits. An IPv6 address will resemble something like this: 4001:0da7:75a3:0000:0000:7a2e:0370:7443. There are three types of IPv6 addresses: unicast addresses, multicast addresses, and anycast addresses. The unicast addresses are IPv6 addresses that refer to a single sender or a single receiver by identifying a unique node on a network. The multicast address is an address that embodies a group of IP devices. This type of IPv6 can only be used as a destination. Lastly, the anycast type of address is the IPv6 address provided for interfaces belonging to distinct network nodes.