Basically, LLDP is the Link Layer Discovery Protocol and it’s a very useful feature in networking. How does it work? Switches and some other devices send out a packet every few seconds with information about the device. For example, a switch will send out its name, type and what port it sends packets from. If another switch gets this packet, it will hang onto that information and you’ll be able to ask the switch about what other switches or networking devices it knows of. It can then report back that there is another switch or device called X with X number of ports as well as its IP address.