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Configuring lldp, Overview, Basic concepts – H3C Technologies H3C S5560 Series Switches User Manual

Page 267: Lldp agent

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Configuring LLDP

You can set an Ethernet interface to work in Layer 3 mode by using the port link-mode route command

(see "Configuring Ethernet interfaces").

Overview

In a heterogeneous network, a standard configuration exchange platform makes sure different types of

network devices from different vendors can discover one another and exchange configuration.
The Link Layer Discovery Protocol (LLDP) is specified 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 as TLV (type, length, and value) triplets in LLDP Data Units (LLDPDUs) to the

directly connected devices. Local device information includes its system capabilities, management IP

address, device ID, and port ID. The device stores the device information in LLDPDUs from the LLDP

neighbors in a standard MIB. For more information about MIBs, see Network Management and
Monitoring Configuration Guide
. LLDP enables a network management system to quickly detect and

identify Layer 2 network topology changes.

Basic concepts

LLDP agent

An LLDP agent is a mapping of an entity where LLDP runs. Multiple LLDP agents can run on the same

interface.
LLDP agents are divided into the following types:

Nearest bridge agent.

Nearest customer bridge agent.

Nearest non-TPMR bridge agent.

A Two-port MAC Relay (TPMR) is a type of bridge that has only two externally-accessible bridge ports,

and supports a subset of the functions of a MAC bridge. A TPMR is transparent to all frame-based
media-independent protocols except for the following:

Protocols destined to it.

Protocols destined to reserved MAC addresses that the relay function of the TPMR is configured not
to forward.

LLDP exchanges packets between neighbor agents and creates and maintains neighbor information for

them.

Figure 71

shows the neighbor relationships for these LLDP agents. LLDP has two bridge modes:

customer bridge (CB) and service bridge (SB).