Types of IPv6 Unicast IP Addresses

D

The correct answer is D. Global.

IPv6 unicast addresses are used to uniquely identify a single interface within a network, and there are three types of IPv6 unicast addresses: global, unique local, and link-local.

Global unicast addresses, which begin with a 2000::/3 prefix, are publicly routable and can be used to communicate across the Internet. They are assigned by the Internet Assigned Numbers Authority (IANA) to Internet service providers (ISPs) and other organizations, which then assign them to individual devices.

Unique local addresses, which begin with a FC00::/7 prefix, are similar to private IP addresses in IPv4 and are intended for use within a single organization or site. They are not routable across the Internet and are designed to be used as internal addresses only.

Link-local addresses, which begin with FE80::/10 prefix, are used to communicate with other devices on the same network segment or link. They are not routable across different network segments or links and are designed for local communication only.

Compatible addresses were used in earlier versions of IPv6 and are no longer used in current implementations. They were used to allow communication between IPv4 and IPv6 networks.

In summary, only global unicast addresses are reachable across the Internet, while unique local and link-local addresses are used for internal communication within an organization or network segment.