Question 90
A router needs to send an IPv6 packet to ALL IPv6 devices on the local link, without enumerating their addresses. What destination is appropriate?
Explanation
Correct Answer
IPv6 uses multicast rather than IPv4-style broadcast. `ff02::1` has link-local scope and identifies all IPv6 nodes on that link. Routers do not forward this link-scoped multicast to distant subnets, so it cannot be used for Internet-wide discovery.
Incorrect Answers
A link-local unicast address targets a specific interface rather than the all-nodes multicast group. It cannot by itself reach all nodes on the LAN.
Global unicast normally denotes one routed interface, not a multicast group. Its prefix does not automatically deliver a packet to all link-local devices.
`ff02::2` targets IPv6 routers, not every attached IPv6 endpoint. It would omit ordinary host recipients that are not routers.