What is the difference between the upcoming IPv6 and IPv4? This article will help you understand it clearly!

What is the difference between the upcoming IPv6 and IPv4? This article will help you understand it clearly!

Due to the rapid development and popularization of the Internet, the original IPV4 address can no longer meet the needs of network users. Although NAT can alleviate the exhaustion of IPV4 addresses, NAT destroys the openness, transparency and end-to-end characteristics of the network environment. Therefore, the IPV6 address protocol came into being. In the near future, IPv6 addresses must be enabled!

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Background of the emergence of IPV6

IPv4 has only about 4.29 billion addresses, but with the development of society, the number of devices that need to connect to the Internet has far exceeded this number.

• July 21, 2013 The Americas region (ARIN) will run out of IPv4 addresses
• July 28, 2012: IPv4 addresses in the European region (RIPE NCC) are exhausted
• IPv4 addresses in the Asia Pacific region (APNIC) are exhausted on April 15, 2011
• June 29, 2014 Latin America and the Caribbean (LACNIC) IPv4 address exhaustion
• October 28, 2014: Africa (AfriNIC) IPv4 address exhaustion

IPv6 is imperative

Advantages of IPV6

1. Larger address space: 128-bit address space can accommodate everyone on the planet

2. No NAT required: ensuring end-to-end communication

3. No broadcast address: including unicast, multicast, and anycast

4. Support mobility and security: Helps ensure compliance with mobile IP and IPsec standards

5. Simpler messages improve router efficiency

6. Interface identification: from the data link layer of the interface

New Features of IPV6

1. Multiple addresses per interface

2. Link-local address: When exchanging routing updates, IGP uses the link-local address as the next hop address

3. Stateless autoconfiguration: An IPV6 device is assigned a unique link-local IPV6 address based on itself

4. Addressing that is independent or not independent of the provider

IPV6 Address

1. An IPv6 address consists of 128 bits, which are represented by eight 16-bit segments. Each 16-bit segment is represented by a hexadecimal number, that is, four hexadecimal digits form a group, separated by colons.

2. The format is: x:x:x:x:x:x:x:x:xx represents 4 hexadecimal digits, for example: 2035:0001:2BC5:0000:0000:087C:0000:000A

3. The IPv6 address consists of two parts: prefix + local identifier

4. Prefix: Add a slash / after the IPV6 address, followed by a decimal number to identify how many bits of the starting bit of an IPV6 address are prefix bits. Generally, the prefix is ​​64 bits, such as: 3ffe:1994:100:a::/64

5. Interface ID: The interface ID is directly derived from the data link layer address of the interface. The ID is globally unique. It is 64 bits long and is dynamically created based on the MAC address.

6. Special IPV6 addresses are as follows:

IPV6 address abbreviation rules:

1. In a field consisting of 4 hexadecimal digits, the leading 0 can be omitted; for example: 09C0=9C0 0000=0

2. In each address, a pair of colons (::) can be used to represent any number of consecutive 0s; for example: ff02:0000:0000:0000:0000:0000:0000:0000:0005=ff02::5

Note: Only one pair of colons can appear in an address, otherwise the address cannot be uniquely determined.

IPV6 address type

Global unicast address format: The network portion provides the location of a device on the downlink dedicated data link, and the host portion provides the identification of the device on this data link. The 16-bit subnet ID field can provide 65536 (216) different subnets

Configuring just a global unicast address will also create a link-local address (EUI-64) on the interface.

Description: Mark bit: The first 3 bits are reserved as 0, the 4th bit: 0-permanent recognized address; 1-temporary address

Range: including: node local-0X1, link local-0X2, region local-0X5, organization local-0X8, global-0XE, reserved-0XF 0X0

Group ID: The first 80 bits are set to 0, and only the last 32 bits are used

Commonly recognized IPv6 multicast addresses: all belong to the permanent link-local scope;