Reference Guide

Link Layer Discovery Protocol (LLDP) | 313
18
Link Layer Discovery Protocol (LLDP)
This chapter contains the following sections:
• Overview
• TIA-1057 (LLDP-MED) Overview
• Configuring LLDP
Overview
Link layer discovery protocol (LLDP)—defined by IEEE 802.1AB—is a protocol that enables a local area
network (LAN) device to advertise its configuration and receive configuration information from adjacent
LLDP-enabled LAN infrastructure devices. The collected information is stored in a management
information base (MIB) on each device, and is accessible via a simple network management protocol
(SNMP).
Protocol Data Units
Configuration information is exchanged in the form of type, length, value (TLV) segments. Figure 18-1
shows the Chassis ID TLV.
• Type—the kind of information included in the TLV
• Length—the value, in octets, of the TLV after the Length field
• Value—the configuration information that the agent is advertising
Figure 18-1. Type, Length, Value (TLV) Segment
Chassis ID Sub-type
fnC0057m
p
Chassis ID
7 bits
9 bits
1 octet
1- 255 octets
TLV Type
(1-127)
TLV Length
Value
TLV Header
0-511 octets