Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 1906)

LLDP, LLDP-MED and Voice VLAN Introduction and Configuration
Software Reference for x310 Series Switches
70.2 AlliedWare Plus TM Operating System - Version 5.4.4C C613-50046-01 REV A
Introduction
This chapter describes the Link Layer Discovery Protocol (LLDP), LLDP for Media Endpoint
Devices (LLDP-MED) and Voice VLAN, and general configuration information for these.
LLDP is designed to be managed with the Simple Network Management Protocol (SNMP),
and SNMP-based Network Management Systems (NMS). LLDP can be configured, and the
information it provides can be accessed, using either the command line interface or SNMP.
■ For detailed descriptions of the commands used to configure LLDP and LLDP-MED,
see
Chapter 71, LLDP Commands .
■ For Voice VLAN commands, see Chapter 17, VLAN Commands .
■ For information about the LLDP and LLDP-MED MIBs, see “Public MIBs” on
page 69.89 .
Link Layer Discovery Protocol
Link Layer Discovery Protocol (LLDP) is a Layer 2 protocol defined by the IEEE Standard
802.1AB-2005. This switch supports LLDP as specified in this standard, including Annex F
and Annex G.
LLDP enables Ethernet network devices, such as switches and routers, to transmit and/or
receive device-related information to or from directly connected devices on the network,
and to store such information learned about other devices. The data sent and received by
LLDP is useful for many reasons. The switch can discover neighbors—other devices
directly connected to it. Devices can use LLDP to advertise some parts of their Layer 2
configuration to their neighbors, enabling some kinds of misconfiguration to be more
easily detected and corrected.
LLDP is a link level (“one hop”) protocol; LLDP information can only be sent to and received
from devices that are directly connected to each other, or connected via a hub or repeater.
Advertised information is not forwarded on to other devices on the network.
The information transmitted in LLDP advertisements flows in one direction only, from one
device to its neighbors, and the communication ends there. Transmitted advertisements
do not solicit responses, and received advertisements do not solicit acknowledgment.
LLDP operates over physical ports (Layer 2) only. For example, it can be configured on
switch ports that belong to static or dynamic aggregated links (channel groups), but not
on the aggregated links themselves; and on switch ports that belong to VLANs, but not on
the VLANs themselves.
LLDP provides a way for the switch to:
■ transmit information about itself to neighbors
■ receive device information from neighbors
■ store and manage information in an LLDP MIB
Each port can be configured to transmit local information, receive neighbor information,
or both.