All devices connected to the Internet are assigned a unique identifier. This identifier, called an IP address is a numerical label that allows other devices to find it. For instance, your home address most probably looks like this: 82.65.211.14.
There exist two types of IP addresses. The IPv4, shown above, is a 32-bit address that uses only decimal numbers 0-9 and the dot character. As such, the total number of possible IPv4 addresses is limited to 232, or 4,294,967,296 unique entries.
With the exponential growth of the Internet and its usage, it became clear that this is not enough for every device connected to the network. As a consequence, the IETF developed a new IP protocol version, called IPv6. The IPv6 protocol uses a hexadecimal system (0-9 and A-F), which allows 340 undecillion IPv6 addresses.
In 2021, despite the lack of IPv4 addresses, IPv6 adoption progresses slowly. About only one-third of the Internet makes use of IPv6:
To summarize, here are the major differences between IPv4 and IPv6:
- IPv4 is a numeric address that consists of 4 fields which are separated by a dot (.) while IPv6 is an alphanumeric address that consists of 8 fields, which are separated by a colon.
- IPv4 is a 32-bit, while IPv6 is a 128-bit address.
- IPv4 is decimal, IPv6 is hexadecimal.
- IPv4 allows a checksum field while IPv6 does not include a checksum.
- IPv4 does not provide Encryption and Authentication, whereas IPv6 does.
- End-to-End connection integrity can't be achieved with IPv4, but it can with IPv6.