IPv6 address types

As you probably know, there are three types of IPv4 addresses: unicast, multicast, and broadcast. In IPv6, broadcast addresses have been eliminated and replaced with anycast and multicast addresses. Here is a list of all address types in IPv6:

• unicast – represents a single interface. Packets addressed to a unicast address are delivered to a single interface.
• multicast – represents a dynamic group of hosts. Multicast addresses in IPv6 have a similar purpose as their counterparts in IPv4 and packets sent to these addresses are delivered to all interfaces tuned into the multicast address.
• anycast – identifies one or more interfaces. For example, servers that support the same function can use the same unicast IP address. Packets sent to that IP address are forwarded to the nearest server. Anycast addresses are often used for load-balancing. Known as one-to-nearest address.

There are three types of unicast addresses in IPv6:

• global unicast – publicly routable IPv6 addresses that work just like public IPv4 addresses.
• link local – similar to the IPv4 addresses from the Automatic Private IP Address (APIPA) range, these addresses are meant to be used only within a network segment that a host is connected to. Routers will not forward packets destined to a link-local address to other links. A link-local IPv6 address must be assigned to every network interface on which the IPv6 protocol is enabled.
• unique local addresses – similar to IPv4 private addresses, IPv6 unique local addresses should be used inside an organization and are not meant to be routed on the Internet.