Zte ZXR10 5900E Series - MAC Address Table Configuration

Chapter3OSPFConguration
StubAreaandTotallyStubbyArea
Whenanon-backboneareadoesnothaveanASBR,arouteronlyhasonepatharriving
toanASexternalnetwork,thatis,apathpassingthroughanABR.Therefore,therouters
belongingtotheseareaswillsendtheLSAssendingtotheunknownhostsoutsidetheAS
toABR.
Inthisway,itisnotrequiredthatoodLSAsoftype5tothearea.Theareadoesnothave
theLSAsoftype4either.Theareaiscalledstubarea.
Inastubarea,allroutersmustbeconguredasstubrouters.AHELLOpacketcontains
a"stubarea"agbit.Theagbitmustbeconsistentamongneighbors.
TheABRinastubareacanlterLSAsoftype5topreventthemfrombeingadvertisedto
stubarea.Inmeantime,theABRgeneratesanLSAoftype3toadvertiseadefaultroute
arrivingtoanASexternaldestinationaddress.
IftheABRalsolterstheLSAoftype3andadvertisesadefaultroutearrivingtoanAS
externaldestinationaddress,theareaiscalledtotallystubbyarea.
Not-So-StubbyArea
ArouterinastubarearefusesLSAsoftype5,soASBRisnotapartofthestubarea.
However,itishopedthatastubareawithanASBRcanbegenerated.Inthisway,routers
intheareacanreceiveASexternalroutesfromtheASBRbelongingtothesamearea,but
theexternalroutinginformationfromotherareaswillbeblocked.
Torealizesuchanarea,OSPFdenesNSSA.InaNSSA,anASBRgeneratesLSAsof
type7insteadtheLSAsoftype5.TheABRcannotsendtheLSAsoftype7toother
OSPFareas.Ontheonehand,itblocksexternalroutestoarrivetheNSSAareaatthe
areaborder.Ontheotherhand,itconvertstheLSAsoftyoe7intotheLSAsoftype5and
sendsthemtootherareas.
OSPFAuthentication
AuthenticationisusedtoexchangepacketsbetweentwoOSPFneighbors.The
authenticationtypeshouldbeconsistentontheOSPFneighbors.Authenticationtypeis
containedbyallpackets.
Authenticationtype"0"indicatesnoauthentication,"1"indicatessimplepassword
authenticationand"2"indicatesMD5encryptionauthentication.
Forplaintextauthentication,aninterfaceonlyallowsapassword.Thepasswordofeach
interfacecanbedifferent,buttheinterfacesinaspecialnetworkmusthavethesame
passwords.ThesimplepasswordissentthroughOSPFpacketsinplaintextmode.
DownBit
WhenMultiprotocolBGP(MP-BGP)routesareredistributedtoOSPFvrfinstanceto
generateLSAs,theoptioneldsoftype-3andtype-5LSAsmustbemarkedasdownbit.
TheLSAsaredisplayedasDownward.Thisisamethodtopreventroutingloopback.
3-7
SJ-20150114102049-003|2015-01-15(R1.0)ZTEProprietaryandCondential