Which IPv6 address type is routable on the Internet and often begins with 2000::/3?

• A. Link-local address
• B. Unique local address
• C. Multicast address
• D. Global address

Answer: (D)

IPv6 uses different address scopes that determine where an address can be used. Link-local addresses, which begin with FE80::, stay on a single local link and are not routable across routers. Unique Local Addresses, starting with FC00::/7, are meant for private networks and aren’t intended to be reachable on the global Internet. Multicast addresses, starting with FF00::/8, are for one-to-many delivery to multiple nodes, not for a single host’s Internet routing. The address type that is designed to be reachable across the global Internet is the global unicast address, allocated from the 2000::/3 prefix. This means many globally routable IPv6 addresses begin anywhere in the 2000:: to 3fff:: range. So, the routable Internet-facing address type is the global (global unicast) address.