Chapter 1 Lldp Configuration; Introduction To Lldp; Overview; Lldp Fundamental - H3C S5500-EI series Operation Manual

Operation Manual – LLDP
H3C S5500-EI Series Ethernet Switches

Chapter 1 LLDP Configuration

When configuring LLDP, go to these sections for information you are interested in:

Introduction to LLDP

LLDP Configuration Tasks List
Performing Basic LLDP Configuration
Configuring LLDP Trap
Displaying and Maintaining LLDP
LLDP Configuration Example
1.1 Introduction to LLDP

1.1.1 Overview

Link Layer Discovery Protocol (LLDP) operates on data link layer. It stores and
maintains the information about the local device and the devices directly connected to it
for network administrators to manage networks through NMS (network management
systems). In LLDP, device information is encapsulated in LLDPDUs in the form of TLV
(meaning type, length, and value) triplets and is exchanged between directly connected
devices. Information in LLDPDUs received is restored in standard MIB (management
information base).

1.1.2 LLDP Fundamental

I. LLDP operating mode
LLDP can operate in one of the following modes.
TxRx mode. A port in this mode sends and receives LLDPDUs.
Tx mode. A port in this mode only sends LLDPDUs.
Rx mode. A port in this mode only receives LLDPDUs.
Disable mode. A port in this mode does not send or receive LLDPDUs.
LLDP is initialized when an LLDP-enabled port changes to operate in another LLDP
operating mode. To prevent LLDP from being initialized too frequently, LLDP
undergoes a period before being initialized on an LLDP-enabled port when the port
changes to operate in another LLDP operating mode. The period is known as
initialization delay, which is determined by the re-initialization delay timer.
II. Sending LLDPDUs
An LLDP-enabled device operating in the TxRx mode or Tx mode sends LLDPDUs to
its directly connected devices periodically. It also sends LLDPDUs when the local
configuration changes to inform the neighboring devices of the change timely. In any of
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Chapter 1 LLDP Configuration