Neighbor Discovery and IPv4 (continued)
IPv6 assumes a redirect next hop is on-link – on the same link that it resides.
IPv6 detects half link failures (neighbors that are suspect or that have gone away).
IPv6 Router advertisements do not contain a Preference field.
Using link-local addresses to identify routers means that this relationship is maintained even if the provider address changes.
Address resolution is accomplished at the ICMP layer.