Final Answer:
The two ICMPv6 message types that must be permitted through IPv6 access control lists to allow the resolution of Layer 3 addresses to Layer 2 MAC addresses are:
1) Neighbor Solicitation (NS)
2) Neighbor Advertisement (NA)
Step-by-step explanation:
Neighbor Solicitation (NS) and Neighbor Advertisement (NA) are crucial ICMPv6 message types for the resolution of Layer 3 (IPv6) addresses to Layer 2 (MAC) addresses in IPv6 networks. These messages are part of the Neighbor Discovery Protocol (NDP), which plays a vital role in IPv6 address resolution and neighbor relationships.
Neighbor Solicitation (NS) is used by a node to discover the link-layer address of a neighboring node, while Neighbor Advertisement (NA) is used by a node to respond to a Neighbor Solicitation and to announce its own link-layer address.
Allowing these ICMPv6 message types through IPv6 access control lists is essential for the proper functioning of IPv6 networks, enabling the resolution of IP addresses to corresponding MAC addresses.