IPv6 addresses are classified into three types:
* Unicast addresses
A unicast address identifies a single network interface. The protocol delivers packets sent to a unicast address to that specific interface. Unicast IPv6 addresses can have a scope which is reflected in more specific address names: global unicast address, link-local address, and unique local unicast address.
* Anycast addresses
An anycast address is assigned to a group interfaces, belonging to different nodes. A packet sent to an anycast address is delivered to just one of the member interfaces, typically the “nearest” according to the routing protocol’s choice of distance. Anycast addresses cannot be identified easily: they have the structure of normal unicast addresses, and differ only by being injected into the routing protocol at multiple points in the network.
* Multicast addresses
A multicast address is also assigned to a set of interfaces that typically belong to different nodes. A packet that is sent to a multicast address is delivered to all interfaces identified by that address. Multicast addresses begin with the first octet being one (1) bits, i.e., they have prefix FF00::/8. The four least-significant bits of the second address octet identify the address scope, i.e. the span over which the multicast address is propagated.
* Unicast addresses
A unicast address identifies a single network interface. The protocol delivers packets sent to a unicast address to that specific interface. Unicast IPv6 addresses can have a scope which is reflected in more specific address names: global unicast address, link-local address, and unique local unicast address.
* Anycast addresses
An anycast address is assigned to a group interfaces, belonging to different nodes. A packet sent to an anycast address is delivered to just one of the member interfaces, typically the “nearest” according to the routing protocol’s choice of distance. Anycast addresses cannot be identified easily: they have the structure of normal unicast addresses, and differ only by being injected into the routing protocol at multiple points in the network.
* Multicast addresses
A multicast address is also assigned to a set of interfaces that typically belong to different nodes. A packet that is sent to a multicast address is delivered to all interfaces identified by that address. Multicast addresses begin with the first octet being one (1) bits, i.e., they have prefix FF00::/8. The four least-significant bits of the second address octet identify the address scope, i.e. the span over which the multicast address is propagated.