networking: LLDP

LLDP - Link Layer Discovery Protocol: is a vendor-neutural, standards-based protocol used to advertise and discover directly connected devices (IEEE 802.1ab).

Informed via LLDP Data Units which contain at least the three following TLV’s (type-length-value):

• Chassis ID
• Port ID
• Time-to-Live (TTL)

LLDP is the standards-based protocol that allows for the discovery and communication between directly connected devices, while TLV's standardize what information can be exchanged.

Example of LLDP TLV's from a Ruckus Switch: