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What is an IP address?

IP address (Internet Protocol Address) refers to the Internet Protocol address, which is also translated as Internet Protocol address. IP address is a unified address format provided by the IP protocol. It allocates a logical address to each network and each host on the Internet to mask differences in physical addresses.

What is the difference between IPv4 and IPv6?

As an important bridge of the Internet, IP is a protocol designed for connecting computer networks to communicate with each other. It is precisely because of the IP protocol that the Internet has rapidly developed into the world's largest and open computer communication network. What are the differences between IPv4 and IPv6? I don't know much. Let's introduce in detail what are the differences between IPv4 and IPv6?

Differences between IPV4 and IPV6:

1. Extend routing and addressing capabilities

   IPv6 increases the IP address from 32 bits to 128 bits, thereby supporting a larger address space. It is estimated that there are 4*10^18 IPv6 addresses per square meter of the earth's surface, so that IP addresses will not be used up in the foreseeable future. IPv6 addresses are encoded using a hierarchical structure similar to CIDR, just like telephone numbers. Streamline routing and speed up routing. A "range" field has been added to the multicast address, so that multicast is not limited to subnets, but can span different subnets and different local area network.

2. Simplification of header format

   Some redundant fields in the IPv4 header format are either dropped or listed as extended headers, reducing the overhead of packet processing and header bandwidth. Although the IPv6 address is 4 times the IPv4 address. But the header is only twice as big.

3. Greater support for options

   IPv6 options are not placed in headers, but in separate extension headers. If you do not specify a router, you will not open the processing extension header. This greatly changes routing performance. IPv6 relaxes strict requirements for the length of options (IPv4 has a maximum length of 40 bytes), and new options can be introduced at any time as needed. Many new features of IPV6 are provided by options, such as support for IP Layer Security (IPSEC), support for Jumbograms, and support for IP Layer Roaming (Mobile-IP).

4. Functions of QoS

   The Internet can not only provide various information and shorten people's distance. You can also have online entertainment. Online VOD is now being hyped up by merchants, but most of them are only at the quasi-VOD level and can only be implemented on the local area network. VOD on the Internet is not ideal. The problem is that although the header of IPv4 has a service type field, this field is actually ignored in current router implementations. In the header of IPv6, there are two corresponding priority and flow identification fields, which allow datagrams to be designated as part of a certain information flow and allow flow control of these datagrams. For example, for real-time communication, even if all packets are lost, the speed must be maintained at a constant speed, so the priority is the highest. However, a news packet is delayed for a few seconds, so its priority is lower. IPv6 specifies these two fields that every IPv6 node must implement.

5. Authentication and confidentiality

   Content on authentication, data consistency and confidentiality has been added to IPv6.

6. Security mechanism IPSec is required

   IPv4 is optional or requires paid support.

7. Enhanced support for mobile devices

   IPv6 was originally designed with the idea of supporting mobile devices, allowing Mobile device to retain the same IP address when switching access points.

8. Support stateless automatic address configuration

   Simplify the address configuration process. Address configuration can be completed without a DNS server, broadcast address prefixes are routed, and each host generates an aggregated global unicast address based on its own MAC address and the received address prefixes. This also makes it easier for hosts in a certain area to change IP address prefixes at the same time.