A host is automatically configuring a link-local IPv6 address with no router present on the segment. Which prefix identifies the address it generates, and what is the defining property of that address?
- Afe80::/10, valid only on the local link and never forwarded by a router Correct
- Bfc00::/7, routable within a single organisation but not on the public internet
- C2000::/3, globally routable and reachable across the public internet
- Dff00::/8, delivered to every interface that has joined the group
Why A is correct: Link-local addresses always come from the fe80::/10 range and an IPv6 router never forwards them off the link, so they remain confined to the local segment - this is the defining property the question asks for.
Why B is wrong: fc00::/7 is the unique local address (ULA) range, which is site-scoped and can be routed between internal subnets; it is not the prefix a host self-assigns for link-local communication, so it is the wrong classification here.
Why C is wrong: 2000::/3 is the global unicast range used for internet-reachable addresses; a host cannot mint a globally routable address without a router advertisement supplying the prefix, so this does not describe the no-router self-configured address.
Why D is wrong: ff00::/8 is the multicast range used for one-to-many delivery, not a unicast address a single host assigns to its own interface; it is a tempting confusion because both are auto-derived, but it is not link-local.