[1]: §1  It operates at the internet layer of the Internet model,[2] and is responsible for gathering various information required for network communication, including the configuration of local connections and the domain name servers and gateways.

[1]: §3.1  For example, it includes Neighbor Unreachability Detection (NUD), thus improving robustness of packet delivery in the presence of failing routers or links, or mobile nodes.

[1] These messages are used to provide the following functionality: IANA maintains a list of all current NDP options as they are published.

[7] Two computers, A and B are connected to the same local area network with no intervening gateway or router.

Typically, network nodes maintain a lookup cache that associates IP and MAC addressees.