Introduction to IPv6 Address

In the 1990s, the IETF think about the growth of the internet and about the limitation and issues with IPv4 and began to look for an alternate. This movement led to the development of IPv6  address (IP version 6 address). IPv6 defeat the limitations of IPv4. IPv6 is a great development with features that better suit current and future network demands.

IPv6 address is the successor to the first Internet Protocol version 4. In contrast to IPv4, which defined an IP address as a 32-bit value, IPv6 addresses have a size of 128 bits. Therefore, IPv6 has a vastly enlarged address space compared to IPv4.

The 32-bit IPv4 address space provides approximately 4,294,967,296 unique addresses. on the other hand the IPv6 address space provides;  340,282,366,920,938,463,463,374,607,431,768,211,456, or 340 undecillion addresses, which is almost equivalent to each particle of sand on Earth.

IPv6 has three types of addresses, which is  following:
  • Unicast addresses. A packet is delivered to one interface.
  • Multicast addresses. A packet is delivered to multiple interfaces.
  • Anycast addresses. A packet is delivered to the nearest of multiple interfaces.

Following are the feature that provides IPv6 address:

  • Increased address space – IPv6 addresses are based on 128-bit hierarchical addressing as compare to IPv4 with 32 bits.
  • Improved packet handling – The IPv6 header has to vary simply with a smaller number of fields as compared to IPv4 packet header.
  • Eliminates the need for NAT – Due to a large number of public IPv6 addresses no NAT is needed. This avoids some of the NAT-induced application problems experienced by applications requiring end-to-end connectivity.


  • Increased Capacity: IPv6 increased the capacity of IP addresses and also easily accommodates additional web addresses.
  • Efficient Routing: IPv6  allows for easy aggregation of prefixes assigned to IP networks. Also, reduces the size of routing tables and makes routing more efficient and hierarchical.
  • More Efficient Packet Processing. IPv6’s simplified packet header makes packet processing more efficient in contrast with IPv4
  • Efficient Data Flow: IPv6 supports multicast rather than broadcast. Multicast allows bandwidth-intensive packet flows to be sent to several destinations simultaneously, saving network bandwidth. 
  • Security: IPv6 security is improved due in part to improved authentication methods built into network firewalls.
  • Simplified Network Configuration: Address auto-configuration (address assignment) is built-in to IPv6. Which makes network configuration simple.
  • Support For New Services: By eliminating Network Address Translation (NAT), true end-to-end connectivity at the IP layer is restored, which enabling new and valuable services.
  • Security: IPSec, which provides confidentiality, authentication and data integrity, is available in IPv6.


  • Conversion: IPv4 is still widely used all over the world and it is a difficult task to convert to IPv6.
  • Readability:  IPv6 Subnetting can be difficult to understand. In contrast to IPv4, It will be much harder to remember the IP addresses.
  • Communication: IPv4 and IPv6 equipment cannot communicate directly to each other, to communicate between IPv4 and IPv4 required more configuration.
  • Transition: The process of making the switch to IPv6 from IPv4 is very slow and boring.
  • IPv6 is not supported in old operating system and devices.
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