background:
IPv4, the Internet protocol referred to as the fourth edition, the address space of a total of 32 (. 4B) , the theoretical total of 2 ^ 32 ( about 4.3 billion ) a ip addresses available for allocation,
Available through CIDR (classless addressing) and NAT (network address translation protocol) to extend the IPv4 address exhaustion time. However, in 2019 Nian 11 Yue 26 days,
The world's 4.3 billion IPv4 addresses have been allocated over, which leads to no other address assigned to the IPS and network infrastructure providers.
The ultimate solution:
IPv6 , (Why not IPv5? (IPv5 exist in the laboratory, there is no popular, and within the home range of IPv4, or IPv4 essence)),
Sixth internet protocol version, the length of the address space 128 (16B) , is 2 ^ (128 - 32) IPv4 of times, astronomical, address definitely enough.
Unlike IPv4 IPv6 salient features of:
1. The address length 128 .
2. simplified ip packet header , header only eight domains (IPv4 12 domain) , the router shortening the time for processing packets, thereby improving throughput of the network.
3. Support for optional fields , speed packet processing.
IPv6 destination address of the packet type:
1. unicast, point to point communication.
2. Multicast, a multipoint communication, to a group of each packet of a computer.
3. anycast packet to a group of computers in the nearest that computer, IPv6 unique.
IPv6 address format:
1. IPv4 dotted decimal, there are four fields, such as 192.168.10.1.
2. IPv6 colon sixteen points , there are eight segments, each field is four hexadecimal numbers (16 × 8), as 5BAC: 1245: 0000.D345: 1234: 1234: 1234: ABCD.
3. zero or a whole field of a first few all zero field may be abbreviated as abbreviated 0000 0, 000A abbreviated as A.
4. Several continuous fields are all 0, a 0 may be further abbreviated.
Transition from IPv4 to IPv6:
1. The dual-stack , so that part of the host (or router) two protocol stacks (IPv4 and the IPv6), by converting dual stack.
2. tunneling , that the whole IPv6 packet into an IPv4 packet to the data portion, using the IPv4 protocol.