What is the difference between IPv4 and IPv6?

ipv4 ipv6
ipv4 ipv6

Last updated: July 3, 2022

If you roam the Internet, at one point or another you must have heard of IPv6 and IPv4. Confused by these words? I explain the difference between IPv4 et IPv6. This article is a bit long, but when finished you will understand what is IPv4, IPv6 and what they are used for.

What is the IP protocol?

 An IP address is the identity of a machine on the Internet. It is a unique address assigned to each machine (i.e. there are no two machines on the Internet with the same IP address).

Likewise, the postal address (last name, first name, street, number, postal code and city) makes it possible to uniquely identify a recipient.

Internet protocol versions

There are currently two versions of Internet Protocol (IP): IPv4 et IPv6. IPv6 is an evolutionary upgrade of the Internet protocol. It will coexist with the old IPv4 for a while.

What is IPv4 (Internet Protocol Version 4)?

IPv4 is the fourth version of the Internet Protocol (IP) used to identify computers on a network.

IPv4 uses a 32-bit address scheme allowing a total of 2^32 addresses (just over 4 billion addresses). As the Internet grows, it is expected that the number of unused IPv4 addresses will eventually run out, as every device – including computers, smartphones and gaming consoles – that connects to the Internet requires an IP address .

What is IPv6 (Internet Protocol Version 6)?

A new Internet Protocol version 6 (IPv6) addressing system is being deployed to meet the need for more Internet addresses.

IPv6 is the successor to Internet Protocol version 4 (IPv4). Designed as an evolutionary upgrade to the Internet Protocol, it will coexist with older IPv4 for some time. IPv6 is designed to allow the Internet to grow gradually, both in terms of the number of hosts connected and the total amount of data traffic transmitted.

It is often referred to as the "next generation" Internet standard and has been under development since the mid-90s. IPv6 was born out of the fear that the demand for IP addresses would outstrip the available supply.

The difference between IPv4 and IPv6 addresses

IPv4 uses a 32-bit address space equivalent to 4 bytes. This means that the total number of IP addresses on the Internet can be up to 2^32. That is, approximately 4,3 billion addresses. It is written in decimal as four digits separated by periods. Each number can be between 0 and 255. For example, could be an IPV4 address.
With IPv6, the number of addresses becomes almost unlimited. It has a large address space of 128 bits. And the total number of unique addresses are 2^128. So the limit of IP addresses is not going to be exceeded for many decades or maybe centuries.
IPv6 addresses are 128-bit IP addresses written in hexadecimal and separated by colons. An example IPv6 address could be written like this: 2ffe:1601:4545:4:345:f8ff:fe35:67bc .
Another difference, to secure IPv4, we have to add a layer like SSL. IPv6 already contains everything needed for security and better guarantees speeds.