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valid ipv6 address

IPv6 Address

IPv6 Address Representation – An Exclusive Explanation

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IPv6 addresses are 128 bits and represented as eight groups of four hexadecimal digits each, each group representing 16 bits. The address can be written in both lowercase and uppercase. The preferred format for writing an IPv6 address is x: x: x: x: x: x: x: x, where each “x” is the group of four hexadecimal digits and each group contains 16 bits. The term used for a group is a hextet.  So each “x” is a single hextet, 16 bits or four hexadecimal digits.

The range of IPv6 addresses are 0000:0000:0000:0000:0000:0000:0000:0000 to FFFF: FFFF: FFFF: FFFF: FFFF: FFFF: FFFF: FFFF. This expression is in hexadecimal. If we convert one hextet into binary, it should be 16 bits. For example, we have a hextet “0000” that is equal to 0000000000000000 (16 time 0s), and hextet “FFFF” is equal to 1111111111111111 (16 tim1 1s). The following is the primary relationship table of binary, decimal, and hexadecimal.

DecimalBinaryHexadecimal
000000
100011
200102
300113
401004
501015
601106
701117
810008
910019
101010A
111011B
121100C
131101D
141110E
151111F

The ideal method of representing IPv6 addresses is groups of eight hextet (32 hexadecimal digits). However, there are two rules we can apply to reduce the number of digits needed to represent an IPv6 address. The preferred format for representing an IPv6 address is the following.

2001 : 0000 : 0000 : 1111 : 1234 : 1000 : A000 : 0100

2001 : 0DA1 : B111 : 0000 : 0000 : ABCD : 0BCD : 1245

FE80 : 0000 : 2BCD : 0000 : 1234 : 4567 : 89AB : CDEF

FE80 : 8BAB : 0000 : 0000 : 0000 : 0000 : 0000 : 0123

FF02 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0001

FE02 : 0000 : ABBB: 0000 : 0000 : 0001 : FF00 : 0200

0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0001

0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000 : 0000

Omitting Leading 0s

Omitting leading 0 is the first rule to reduce the notation of the IPv6 address. Following are the examples to omit any leading 0s (zeros) in any 16-bit section or hextet:

  • 0100 can be represented as 100
  • 0DA1 can be represented as DA1
  • 0123 can be represented as 123
  • 0000 can be represented as 0

This rule only omits leading 0s, not trailing 0s. Otherwise, the address would be ambiguous. The table below shows examples of omitting leading 0s from the IPv6 address.

IPv6 Address

Omit All 0 Segments

The second rule reduces the notation of IPv6 addresses using a double colon (::) that can replace any single, contiguous string of one or more hextet containing all 0s. The double colon (::) can only be used once within an address; otherwise, there would be more than one possible resulting address. For example, if we have an IPv6 address FE02: 0000 : ABBB: 0000: 0000: 0001: FF00: 0200 and we apply the technique like FE02:: ABBB:: 1: FF00: 200. It is not correct. When used with the omitting leading 0s technique, the notation of the IPv6 address can often be greatly reduced. This is commonly known as the compressed format.

IPv6 Address

Prefix Length Notation

The most left bits of the IPv6 address and the network bits length represented in CIDR format are known as the network prefix. The prefixes in IPv6 are used similarly to the subnet mask of IPv4 addresses. In IPv6, we use a notation similar to the CIDR mask representation in IPv4. The notation values are between 1 and 128 to represent the network bits.

For example, in IPv6 address 2001: ABC8: 1000: 000C: 0000: 0000: 0000: 0001/ 64, 2001: ABC8: 1000: 000C::/64 represents the network prefix and the range for this IP network is from 2001: ABC8: 1000: 000C: 0000: 0000: 0000: 0001/64 to 2001: ABC8: 1000: 000C: ffff: ffff: ffff: ffff/64.

The first three hextet (48 bits ) 2001:ABC8:1000 are the IP version 6 global routing prefix, and the next 16 bits(hextet) “000C ” is used for internal subnetting within an organization, and the last 64 bits are used for internal hosts of the network. The length of the IPv6 prefix is used to recognize how many bits of a Global Unicast IP version 6 address are in the network.

Introduction to IPv6 Addresses

Introduction to IPv6 Addresses

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In the 1990s, the IETF thought about the development of the internet and the limitations and issues with IPv4 (as we discussed earlier) and began to look for an alternative. This movement led to the IPv6 address (IP version 6 addresses). IP version 6 addresses defeat the limitations of IPv4 addresses. It is a great development with features that better suit current and future network demands. It is the successor to the first Internet Protocol version 4.

In contrast to IPv4, which defined an IP address as a 32-bit value, IP version 6 addresses have a size of 128 bits. Therefore it has a vastly enlarged address space compared to IPv4. The 32-bit IPv4 address space provides approximately 4,294,967,296 unique addresses. However, the IP version 6 address space provides 340,282,366,920,938,463,463,374,607,431,768,211,456, or 340 undecillion addresses, which is almost equal to each particle of sand on Earth.

IP version 6 has three types of addresses, which are the 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.

The features provide IPv6 address.

  • Increased address space—IP version 6 addresses have 128-bit hierarchical addressing, compared to IP version 4, which has 32 bits.
  • Improved packet handling—The IP version 6 header has to be very simple, with a smaller number of fields compared to the IP version 4 packet header.
  • Eliminates the need for NAT—Due to the many public IP version 6 addresses, no NAT is needed. This avoids some of the NAT-induced application problems experienced by applications requiring end-to-end connectivity.

Advantages

  • Increased Capacity:  IP version 6 increased  IP addresses and easily accommodates more web addresses.
  • Efficient Routing: IP version 6  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: IP version 6 supports multicast and not broadcast. Multicast allows bandwidth-intensive packet flows to be sent to several destinations simultaneously, saving network bandwidth.
  • Security: IP version 6 improved due partly to improved authentication methods built into network firewalls.
  • Simplified Network Configuration: Address auto-configuration (address assignment) is built into 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 enables new and valuable services.
  • Security: IPsec, which provides confidentiality, authentication and also data integrity, is available in IP version 6.

Disadvantages

  • Conversion: IPv4 is still widely used worldwide, and it is difficult to convert to an IPv6 Address.
  • Readability:  IPv6 Subnetting can be difficult to understand. In contrast to IPv4, remembering the IP addresses will be much harder.
  • Communication: IPv4 and IPv6 equipment cannot communicate directly with each other, to communicate between IPv4 and IPv4 required more configuration.
  • Transition: The process of switching to IPv6 from IPv4 is very slow and boring.
  • IPv6 Address is not supported in the old operating system and devices.