Link Layer Discovery Protocol (LLDP)

Link Layer Discovery Protocol (LLDP) is an IEEE 802.1AB-2009 that defines messages, encapsulated in Ethernet frames for the purpose of giving devices a means of announcing basic device information to other devices on the LAN (Local Area Network) through periodic retransmissions out each port every 30 seconds by default.

This implementation of LLDP is compatible with the IEEE 802.1AB-2005 standard. LLDP uses Layer 2 (the data link layer), and allows network management applications to extend their awareness of the network by discovering devices that are direct neighbors of already known devices.

With LLDP, the switch can advertise the presence of its ports, their major capabilities, and their current status to adjacent LLDP neighbours. LLDP transmissions occur on ports at regular intervals or whenever there is a relevant change to their status. The switch can also receive LLDP information advertised from adjacent LLDP-capable network devices.

The following topics provide more information on configuring LLDP:

Enabling LLDPDisplaying LLDP Neighbors