LLDP

链路层发现协议（Link Layer Discovery Protocol，LLDP）是一种数据链路层协议，网络设备可以通过在本地网络中发送LLDPDU（Link Layer Discovery Protocol Data Unit）来通告其他设备自身的状态。是一种能够使网络中的设备互相发现并通告状态、交互信息的协议。

The Link Layer Discovery Protocol (LLDP) is a vendor-neutral link layer protocol used by network devices for advertising their identity, capabilities, and neighbors on an IEEE 802 local area network, principally wired Ethernet.[1] The protocol is formally referred to by the IEEE as Station and Media Access Control Connectivity Discovery specified in IEEE 802.1AB and IEEE 802.3 section 6 clause 79.[2]

LLDP performs functions similar to several proprietary protocols, such as Cisco Discovery Protocol, Foundry Discovery Protocol, Nortel Discovery Protocol and Link Layer Topology Discovery.