Zte ZXR10 5900E Series - Figure 4-1 IS-IS Architecture

ZXR105900ESeriesCongurationGuide(IPv4Routing)
LSPexistingintheSNP ,itwillsendaSNPinmulticastmodetoaskfortherequiredLSP
fromotherroutersonthenetwork.
ByusingLSPsinconjunctionwithSNPs,IS-ISprotocolcaninteractroutesreliablyona
largenetwork.
Likewise,IS-ISprotocolalsousestheDijkstraSPFalgorithmtocalculateroutes.Based
onthelinkstatedatabase,itusestheSPFalgorithmtocalculatetheoptimalrouteand
thenaddstheroutetoIProutingtable.
IS-ISOperationPrinciple
BasicIS-ISConcepts
lAreapartition
TheIS-ISdynamicrouteprotocolusesalayeredtopologyarchitecture.Thenetwork
consiststwolayerstoreducetheloadoftherouter.Thisarchitecturecanbettermeet
therequirementsoflargescalenetworkapplications.Forthearchitecture,seeFigure
4-1.
Figure4-1IS-ISArchitecture
TheIS-ISarchitectureconsistsoftwolayers:L1andL2.TheL2layerconsistsofL2
routers.Itoperatesasthebackbonenetwork.TheL1layerconsistsofL1routersand
L1/L2routers.Itoperatesasanon-backbonenetwork.L1routerscanonlyexchange
routinginformationwithL1routersandL1/L2routersinthisarea.
4-2
SJ-20150114102049-003|2015-01-15(R1.0)ZTEProprietaryandCondential