Description of IPv6 address representation)

IPv6It was the sixth version of Internet protocol. It was first known as the next-generation Internet Protocol (IPng) in the IPng selection process of IETF. IPv6 is the second version of Internet Protocol widely used.

The existing standard IPv4 only supports about 4 billion (4 × 109) network addresses, while IPv6 supports 3.4 × 1038 network addresses, this is equivalent to 4.3X1020 addresses (6.7x1017 addresses/mm2) per square inch on the earth ). (Ipv5 is not an IPv4 inheritance, but an experimental stream-oriented data stream protocol used to provide support for sound and images .)

IPv6 address Representation

The IPv6 address is 128-bit long, but usually eight groups are written, each of which is in the form of four hexadecimal numbers. For example:

2001:0db8:85a3:08d3:1319:8a2e:0370:7344

Is a valid IPv6 address.

If all four digits are zero, they can be omitted. For example:

2001:0db8:85a3:0000:1319:8a2e:0370:7344

Equivalent

2001:0db8:85a3::1319:8a2e:0370:7344

To comply with these rules, if there are more than two colons due to omission, You can compress them into one, but this type of zero compression can only appear once in the address. Therefore:

2001:0DB8:0000:0000:0000:0000:1428:57ab2001:0DB8:0000:0000:0000::1428:57ab2001:0DB8:0:0:0:0:1428:57ab2001:0DB8:0::0:1428:57ab2001:0DB8::1428:57ab

Make valid addresses, and they are equivalent. However

             2001::25de::cade

It is invalid. (This will make it hard to figure out how many groups are completely empty in each compression)

The leading zero can be omitted at the same time. Therefore:

2001: 0db8: 02de: 0e13 is equivalent

               2001:DB8:2de::e13

If the address is actually an IPv4 address, the last 32 bits can be expressed in a decimal number. Therefore:

FFFF: 192.168.89.9 is equivalent to: FFFF: c0a8: 5909, but not to: 192.168.89.9 and: c0a8: 5909.

The FFFF: 1.2.3.4 format is IPv4 image addressIs not recommended. The format 1.2.3.4 is IPv4 consistent address.

The IPv4 address can be easily converted to the IPv6 format. For example, if an IPv4 address is 135.75.43.52 (0x874b2b34 in hexadecimal format), it can be converted to 0000: 0000: 0000: 0000: 0000: 874b: 2b34 or:: 874b: 2b34. You can also use a mixed sign (IPv4-compatible address), which can be: 135.75.43.52.