Switch User Manual

Configuring Link Layer Discovery Protocol and LLDP-MED
SecureStack C3 Configuration Guide 6-13
Examples
ThisexampleshowshowtoclearalltheCiscoDPparametersbacktothedefaultsettings.
C3(rw)->clear ciscodp
ThisexampleshowshowtocleartheCiscoDPstatusonportge.1.5.
C3(rw)->clear ciscodp port status ge.1.5
Configuring Link Layer Discovery Protocol and LLDP-MED
Overview
TheLinkLayerDiscoveryProtocol(LLPD)providesanindustrystandard,vendor‐neutralwayto
allownetworkdevicestoadvertisetheiridentitiesandcapabilitiesonalocalareanetwork,andto
discoverthatinformationabouttheirneighbors.
LLDP‐MEDisanenhancementtoLLDPthatprovidesthefollowingbenefits:
•Auto‐discoveryofLAN
policies,suchasVLANid,802.1ppriority,andDiffServcodepoint
settings,leadingto“plug‐and‐play”networking
•Devicelocationandtopologydiscovery,allowingcreationoflocationdatabasesand,inthe
caseofVoIP ,provisionofE911services
•Extendedanda utoma tedpowermanagementofPoweroverEthernetendpoints
•Inventorymanagement,allowingnetworkadministrators
totracktheirnetworkdevicesand
todeterminetheircharacteristics,suchasmanufacturer,softwareandhardwareversions,and
serialorassetnumbers
TheinformationsentbyanLLDP‐enableddeviceisextractedandtabulatedbyitspeers.The
communicationcanbedonewheninformationchangesoronaperiodicbasis.The
information
tabulatedisagedtoensurethatitiskeptuptodate.Portscanbeconfiguredtosendthis
information,receivethisinformation,orbothsendandreceive.
EitherLLDPorLLDP‐MED,butnotboth,canbeusedonaninterfacebetweentwodevices.A
switchportusesLLDP
‐MEDwhenitdetectsthatanLLDP‐MED‐capabledeviceisconnectedtoit.
LLDPinformationiscontainedwithinaLinkLayerDiscoveryProtocolDataUnit(LLDPDU)sent
inasingle8 02.3Ethernetframe.TheinformationfieldsinLLDPDUareasequenceofshort,
variable‐length,informationelementsknownasTLVs
—type,length,andvaluefieldswhere:
•Typeidentifieswhatkindofinformationisbeingsent
•Lengthindicates thelengthoftheinformation stringinoctets
•Valueistheactualinformationthatneedstobesent
TheLLDPstandardspecifiesthatcertainTLVsaremandatoryintransmittedLLDPDUs,while
othersareoptional.
Youcanconfigureonaport‐specificbasiswhichoptionalLLDPandLLDP‐
MEDTLVsshouldbesentinLLDPDUs.
Purpose
ToreviewandconfigureLLPDandLLPD‐MED.