Link Layer Discovery Protocol, or LLDP is a relatively new protocol allowing a network device to announce its presence, advertise capabilities and identity itself to the network.

LLDP was introduced as a vendor-neutral protocol, that can be used instead of a number of proprietary protocols. LLDP-enabled devices periodically send their information to a multicast address, in the form of a Ethernet frame. This can be monitored, thus making network discovery more efficient.