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: