What two ICMPv6 message types must be allowed through IPv6 access control lists to enable resolution of Layer 3 addresses to Layer 2 MAC addresses? (Choose two.)

To enable the resolution of Layer 3 addresses to Layer 2 MAC addresses in an IPv6 network, the two essential ICMPv6 message types that need to be permitted are Neighbor Solicitation and Neighbor Advertisement messages.

Neighbor Solicitation messages are used by a device to determine the link-layer address (MAC address) of a neighboring device when it only knows the IPv6 address. This is crucial for establishing communication at the link layer, as the IPv6 addresses must be mapped to their corresponding MAC addresses to form valid Ethernet frames.

Neighbor Advertisement messages are sent in response to Neighbor Solicitation messages. These messages contain the MAC address of the targeted IPv6 address, confirming its identity and facilitating the communication process. This exchange is part of the Neighbor Discovery Protocol (NDP) used in IPv6 for operations such as address autoconfiguration and discovering other nodes on the network.

While Echo requests and Router advertisements serve important functions in IPv6 networking, they are not directly involved in the resolution of Layer 3 addresses to Layer 2 MAC addresses, which is why they are not needed for this specific purpose. Echo requests are primarily used for testing reachability with the ping utility, while Router advertisements are part of the router discovery process for informing hosts about the presence