Link Layer Discovery Protocol (LLDP)
The Link Layer
Discovery Protocol (LLDP) is a neighbor discovery protocol used by
network devices to advertise their identity, capabilities, and interconnections
on an IEEE 802 LAN network. LLDP is vendor-neutral. The protocol defines
a standard way for Ethernet devices to advertise information about
themselves to their network neighbors, and store the information they
discover from other devices.
LLDP operates above the MAC service
layer and can be used in any networking device that implements a MAC
service. Information gathered with LLDP is stored in the device in
a standard management information database (MIB) and can be queried
with the Simple Network Management Protocol (SNMP). For example, a
LAN switch and a router advertise chassis/port IDs and system descriptions
to each other. The devices store the information they learn about
each other in local MIB databases accessible through SNMP. The network
management system retrieves the data stored by each device and builds
a network topology map.