How many digits are addresses extended to in ipv6?

The address in ipv6 is extended to 128 bits. IPv6 address is a binary number expressed in hexadecimal. An IPv6 IP address consists of 8 address sections, each section contains 16 address bits, and the total length is "16x8=128"; therefore, the IPv6 protocol has a 128-bit address length. , which is 4 times the length of the IPv4 address.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

The address in ipv6 is extended to 128 bits.

IPv6 is the abbreviation of "Internet Protocol Version 6" in English. It is the next generation IP protocol designed by the Internet Engineering Task Force (IETF) to replace IPv4. Its address The quantity claims to be able to assign an address to every grain of sand in the world.

The biggest problem of IPv4 is the insufficient network address resources, which seriously restricts the application and development of the Internet. The use of IPv6 can not only solve the problem of the number of network address resources, but also solve the obstacles for multiple access devices to connect to the Internet.

IPv6 is designed to replace IPv4. However, IPv4 has still occupied a dominant position in Internet traffic for a long time, and the use of IPv6 has grown slowly. In April 2022, the percentage of users using Google services through IPv6 exceeded 40% for the first time.

The IPv6 address length is 128 bits, which is four times the IPv4 address length. An IPv6 IP address consists of 8 address sections, each section contains 16 address bits, and the total length is 16x8=128 bits.

So the IPv4 dotted decimal format is no longer applicable and is represented in hexadecimal.

IPv6 has 3 representation methods:

1. Hexadecimal representation

The format is X:X:X:X:X:X:X:X, where each X represents 16b in the address, expressed in hexadecimal, for example:

ABCD:EF01: 2345:6789:ABCD:EF01:2345:6789

In this notation, the leading 0 of each X can be omitted, for example:

2001:0DB8:0000:0023: 0008:0800:200C:417A→ 2001:DB8:0:23:8:800:200C:417A

2. 0-bit compressed representation

in a certain In some cases, an IPv6 address may contain a long period of 0s, and the continuous period of 0s can be compressed into "::". However, to ensure the uniqueness of address resolution, "::" can only appear once in the address, for example:

FF01:0:0:0:0:0:0:1101 → FF01::1101

0:0:0:0:0:0:0:1 → ::1

0:0:0:0:0:0:0:0 → ::

3. Embedded IPv4 address representation

In order to achieve IPv4-IPv6 interoperability, the IPv4 address will be embedded in the IPv6 address. At this time, the address is often expressed as: X:X:X ::X: Typical example, note that in the first 96b, the method of compressing 0 bits is still applicable

Address type

The IPv6 protocol mainly defines three types Address types: Unicast Address (Unicast Address), Multicast Address (Multicast Address) and Anycast Address (Anycast Address). Compared with the original IPv4 address, a new type of "anycast address" is added, and the broadcast address in the original IPv4 address is cancelled, because the broadcast function in IPv6 is completed through multicast.

Unicast address: Used to uniquely identify an interface, similar to the unicast address in IPv4. Datagrams sent to a unicast address will be delivered to an interface identified by this address.

Multicast address: used to identify a group of interfaces (usually this group of interfaces belong to different nodes), similar to the multicast address in IPv4. Datagrams sent to a multicast address are delivered to all interfaces identified by this address.

Anycast address: used to identify a group of interfaces (usually this group of interfaces belong to different nodes). Datagrams sent to an anycast address are delivered to the interface in the set of interfaces identified by this address that is closest to the source node (as measured by the routing protocol in use).

IPv6 address type is determined by the address prefix part. The correspondence between the main address types and address prefixes is as follows:

Anycast address ## is allocated from the unicast address space, Using the format of unicast addressFAQ column!

Address Type		Address Prefix (Binary)	IPv6 Prefix Identification
Unicast address	Unspecified address	00…0(128 bits)	::/128
	Loopback address	00…1(128 bits)	::1/128
	Link local address	1111111010	FE80::/10
	Unique local address	1111 110	##FC00::/7 (including FD00::/8 and Uncommonly used FC00::/8)
	Site local address (deprecated, replaced by unique local address)	1111111011	FEC0::/10
	Global unicast address	Other forms	-
##Multicast Address	#11111111	##FF00::/8
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