Currently, IPv4 is IP addressing method used in networking. IPv4 is 32 bit length. Unfortunately, the number of public addresses is almost depleted. We have more and more devices connected to the internet everyday. So, in near future we will suffer lack of public IPv4 addresses.

IPv6 origin

Luckily, in 90s, IPv6 (Internet protocol version 6) has been created. It’s 128 bit length. With this technology we can address 2128 devices. IPv6 is written as hexadecimal number with colon every 16 bits.

For example:


Next to “Link-local IPv6 Address” you can see my current local IPv6 address.

Reserved addresses

IPv6, as well as IPv4, has some addresses that are taken by default.

  • ::/128 is address that has 0 bits.
  • ::1/128 is a loopback
  • ::/96 pool of addresses that provides compatibility with IPv4
  • 2001:db8::/32 it’s used only in docs. Cannot be used for external software.
  • 2002::/24 are addresses that have been created based on IPv4

Latest operating systems are equipped with IPv6 service. Although, we are still using IPv4 we should be prepared to change our IP addressing habits in near future.

This article will be improved in time. For the time being we should focus on current addressing method.