1 lldp configuration, Overview, Background – H3C Technologies H3C S5120 Series Switches User Manual
Page 125: Basic concepts, Lldpdus, Lldp configuration

1-1
1
LLDP Configuration
This chapter includes these sections:
z
z
z
Performing Basic LLDP Configuration
z
z
z
Displaying and Maintaining LLDP
z
Overview
Background
In a heterogeneous network, it is important that different types of network devices from different vendors
can discover one another and exchange configuration for interoperability and management sake.
Therefore, a standard configuration exchange platform was created.
The IETF drafted the Link Layer Discovery Protocol (LLDP) in IEEE 802.1AB. The protocol operates on
the data link layer to exchange device information between directly connected devices. With LLDP, a
device sends local device information (including its major functions, management IP address, device ID,
and port ID) as TLV (type, length, and value) triplets in Link Layer Discovery Protocol Data Units
(LLDPDUs) to the directly connected devices, and at the same time, stores the device information
received in LLDPDUs sent from the LLDP neighbors in a standard management information base (MIB).
It allows a network management system to fast detect Layer-2 network topology change and identify
what the change is.
For more information about MIBs, see SNMP Configuration in this manual.
Basic Concepts
LLDPDUs
LLDP sends device information in LLDP data units (LLDPDUs). LLDPDUs are encapsulated in Ethernet
II or Subnetwork Access Protocol (SNAP) frames.
1) Ethernet II-encapsulated LLDPDU format