IPv6 address ( Internet Protocol Version 6 address ) is a digital label used to identify the network interface of a computer or any other network node operating on an IPv6 network .
IPv6 addresses are used to identify the network interfaces of a node, which allows other nodes to send IPv6 packets to a specific node or group of nodes.
IPv6 is intended to replace the IPv4 protocol that is widely used on the Internet . Unlike IPv4, which uses 32-bit addresses, IPv6 uses 128-bit addresses. Therefore, IPv6 has a significantly larger address space than IPv4.
Content
Types of IPv6 Addresses
IPv6 addresses can be classified by addressing method: unicast ( Unicast ), Anycast and multicast ( 1) .
- Unicast addresses identify only one network interface. IPv6 delivers packets sent to that address to a specific interface.
- Anycast addresses are assigned to a group of interfaces, usually belonging to different nodes. A packet sent to such an address is delivered to one of the interfaces of this group, as a rule - the one closest to the sender from the point of view of the routing protocol .
- A multicast address is also used by a group of nodes, but a packet sent to that address will be delivered to each node in the group.
IPv6 does not implement broadcast addresses. The traditional role of broadcasting is realized using multicasting to the address ff02 :: 1 , however, the use of this group is not recommended.
Address Structure
Unicast and Anycast Address Structure
Unicast and Anycast addresses typically consist of two logical parts: the 64-bit network prefix used for routing and the 64-bit interface identifier used to identify the host network interface.
| bits | 48 (or more) | 16 (or less) | 64 |
|---|---|---|---|
| field | routing prefix | subnet id | interface identifier |
The network prefix (a combination of the routing prefix fields and the subnet id ) is contained in the upper 64 bits of the address. The size of the routing prefix can increase, taking the address bits from the subnet id field. The bits of the subnet id field can be used by the network administrator to create subnets . The interface identifier field can be obtained in one of the following ways:
- Automatically generated from MAC address using modified EUI-64;
- Received from a DHCPv6 server
- automatically set randomly;
- manually configured.
Local ( English Link-local ) addresses are also based on the interface identifier, but use a different network prefix format.
| bits | ten | 54 | 64 |
|---|---|---|---|
| field | prefix | zeros | interface identifier |
The prefix field contains the binary value 1111111010 , and 54 zeros make the network prefix the same for all networks, which makes local addresses non-routable.
Multicast Address Structure
Multicast address is formed in accordance with several rules, depending on the application.
| bits | eight | four | four | 112 |
|---|---|---|---|---|
| field | prefix | flg | sc | group ID |
The prefix field contains the binary value 11111111 in any multicast address.
See also
- IPv6
- IPv4
- IPv5
- Teredo - IPv6 to IPv4 UDP Encapsulation Protocol
- 6to4 - IPv6 Encapsulation Protocol in IPv4
- 6rd - IPv4 to IPv6 migration mechanism within the same network
- TCP / IP
- SCTP
- IPv6 International Day
- IPv6 Pack
Notes
- ↑ R. Hinden, S. Deering (February 2006) IP Version 6 Addressing Architecture , IETF . RFC 4291 .