Link Layer Discovery Protocol

The Link Layer Discovery Protocol (LLDP) is a link-layer protocol used by network devices for advertising their identity, capabilities, and neighbors on a local area network based on IEEE 802 technology, principally wired Ethernet. The protocol is defined in technical standards and is formally referred to by the IEEE as Station and Media Access Control Connectivity Discovery specified in IEEE 802.1AB with additional support in IEEE 802.3 section 6 clause 79.

Source: Wikipedia — Link Layer Discovery Protocol (CC BY-SA 4.0)