IPv6 and IPv6 Addresses

IPv6 Interface ID with EUI64 Format

IPv6 and IPv6 Addresses

IPv4 is most widespread implementation of IP protocol. It has 32 bit adress space, so it allow to use almost 232=4,294,967,296 addresses in internet. Because of the fact that these addresses are almost run out a new version of IP, IPv6 revealed.

These IPv4 addresses are run out of although CIDR,NAT,Priviate Addresses techniques are used to alleviate this shorthage.

The middle one, IPv5 is used for “Internet Streaming Protocol” for research and development, so IP protocol developers continue the way with version 6.

The new and the next generation version of IP, IPv6 has 128 bit address space.So there are almost 2128 available addresses for this devices.This is almost 340 undecilion available addresses, nearly unlimited.

To sum up the features coming with the IPv6;

  • Increased address space
  • Simplified configuration (with auto configuration)
  • Integrated security (IPSec)
  • Backward compatibility with IPv4


Different than IPv4, IPv6 addresses written with hexadecimal digits.This address is consist of eight colons and in each colons there are four digits.So the address become 8*4*4bit = 128 bit.An example of an IPv6 address is below:

There are some abbreviations while writing an IPv6 address.These abbreviations are mentioned below :
      1. • Leading zeros can be dropped like below:

      1. • If we have an entire field of zeros we can use only one 0 for each colon:

      1. • If we have a set of contiguous zero fields we can use

double colons(::)

      1. instead:
      1. (double colons can be used only one time in an address)



IPv6 address always use CIDR(Classless Inter Domain Routing) to detrmine the prefix:

IPv6 unicasts generally allocate the first 64 bits of the address to identify the prefix and the remainning 64 bits are identify the host portion.This interface ID is based on the interface’s hardware address.This interface ID can be produced by EUI-64 format.

To sum up this format assume that we have a MAC address of 1111.2222.3333.Follow the steps in the below picture to produce an IPv6 InterfaceID from this MAC address:

IPv6InterfaceIDwithEUI64Format - IPv6 and IPv6 Addresses

IPv6 – Part 1 (IPv6 and IPv6 Addresses)
IPv6 – Part 2 (What does IPv6 bring?)
IPv6 – Part 3 (Address Types in IPv6)
IPv6 – Part 4 (Subnetting IPv6)

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