Which statement best describes the scope values used by IPv6 multicast addresses?

• A. Global and local
• B. Node-local, Link-local, Site-local (deprecated), Organization-local, and Global
• C. Unicast and multicast
• D. Private and public

Answer: (B)

IPv6 multicast uses defined scope values to tell where a multicast packet can be delivered. The typical set, from most local to most global, is node-local (interface-local), link-local, site-local (deprecated), organization-local, and global. Node-local means the packet stays on the local node. Link-local confines it to the same physical link, so it won’t be forwarded by routers. Site-local was intended for an entire site but is deprecated because its boundaries were unclear. Organization-local covers multicast within an organizational network, potentially spanning multiple sites but not the public Internet. Global makes the multicast routable across the Internet.

This combination—node-local, link-local, site-local (deprecated), organization-local, and global—best describes the IPv6 multicast scope values. The other choices don’t reflect the full set of scopes or mix in terms that don’t apply to IPv6 multicast.