To allow only devices with registered IPv6 addresses and connecting from assigned locations, which IPv6 security feature is required?

IPv6 Prefix Guard is the correct feature because it prevents unauthorized devices from using prefixes not assigned to their segment. It validates the source IPv6 prefix of incoming packets against a list of allowed prefixes for that interface. This ensures that only devices with registered IPv6 addresses (from assigned prefixes) can communicate. IPv6 Snooping focuses on validating Neighbor Discovery Protocol (NDP) messages, primarily for preventing address spoofing and DoS attacks, not prefix validation. IPv6 Destination Guard protects against traffic destined for unassigned or unauthorized IPv6 addresses within a segment, but doesn't validate the source prefix. IPv6 Router Advertisement Guard prevents rogue router advertisements, which is about controlling routing information, not source prefix validation.