Types of IPv6 Addresses, Global Unicast, Link-local, Multicast, Anycast, Loopback addresses

IPv6 has several types of addresses, some of which are explained below.

• Global Unicast IPv6 addresses: Used to identify a single interface. These are standard globally unique unicast addresses (public IPv4 addresses) as in IPv4, one per host interface. Global Unicast IPv6 addresses are internet routable IPv6 addresses.

• Link Local IPv6 addresses: Link Local IPv6 addresses allow communications between devices on a local link. Link Local IPv6 addresses are not routable. They are used on a subnet. Normal Link Local IPv6 address prefix is fe80::/10.

• Multicast: A multicast address identifies zero or more interfaces on the same or different hosts. A multicast transmission sends packets to all interfaces that are part of a multicast group. The group is represented by the IPv6 destination address of the packet. IPv6 multicast addresses start with FF. Following are the important IPv6 multicast addresses.

ff02::1 - All nodes on the local network segment

ff02::2 - All routers on the local network segment

• Anycast: An anycast address identifies multiple interfaces. An anycast transmission sends packets to only one of the interfaces associated with the address, not to all of the interfaces. This interface is typically the closest interface, as defined by the routing protocol.

• Loopback: Used by a node to send an IPv6 packet to itself. An IPv6 loopback address functions the same as an IPv4 loopback address. The IPv6 loopback address is 0000:0000:0000:0000:0000:0000:0000:0001/128, which can be also represented as ::1.