# LLDP

**链路层发现协议**（Link Layer Discovery Protocol，LLDP）是一种[数据链路层](https://zh.wikipedia.org/wiki/%E6%95%B0%E6%8D%AE%E9%93%BE%E8%B7%AF%E5%B1%82)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](https://en.wikipedia.org/wiki/Link_layer) protocol used by network devices for advertising their identity, capabilities, and neighbors on an [IEEE 802](https://en.wikipedia.org/wiki/IEEE_802) local area network, principally [wired Ethernet](https://en.wikipedia.org/wiki/Wired_Ethernet).[\[1\]](https://en.wikipedia.org/wiki/Link_Layer_Discovery_Protocol#cite_note-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**.[\[2\]](https://en.wikipedia.org/wiki/Link_Layer_Discovery_Protocol#cite_note-2)

LLDP performs functions similar to several [proprietary protocols](https://en.wikipedia.org/wiki/Proprietary_protocol), such as [Cisco Discovery Protocol](https://en.wikipedia.org/wiki/Cisco_Discovery_Protocol), [Foundry Discovery Protocol](https://en.wikipedia.org/wiki/Foundry_Discovery_Protocol), [Nortel Discovery Protocol](https://en.wikipedia.org/wiki/Nortel_Discovery_Protocol) and [Link Layer Topology Discovery](https://en.wikipedia.org/wiki/Link_Layer_Topology_Discovery).
