Zte ZXR10 2928E-PS

ZXR102900ESeriesCongurationGuide
Figure4-9MSTPTopologicalStructure
SpanningTreeProtocol(STP)cancalculateaccordingtotheprotocol.Portsaredivided
intodifferentparts:
lMaster:TheporttypeisintroducedinMSTPprotocol.Whenthemultipledifferent
areasexist,themainportistheminimalpathcostportpointtotheroot.
lRoot:Theportthathastheminimalcosttorootbridgeandtakeschargeinforwarding
datatorootnode.Whenmultipleportshavethesamecosttotherootbridge,then
theportwiththelowestportprioritybecomestotherootport.
lDesignated:Theporttransmitsdatatoswitchdownward,andsendsSTPprotocol
messagetomaintainthestateofSTP .
lBackup:TheportreceivestheSTPmessage,whichprovesthatthereexitsaloop
routetotheportitself.
lAlternate:TheportreceivesexcessSTPprotocolmessagefromotherequipment.
However,whentheoriginallinkabnormallylost,theportunderthisstatecantransfer
totransmittingstateandmaintainthenetworkinsteadoftheportlapsed.
lEdged:Theportisusedtoconnecttheterminalequipment,suchasPC.Theport
doesnotparticipateincalculationbeforeSTPisstable,andthestatecanbeswitched
fast.
Accordingtoportrole,thestateafterthecalculationbeingsteadyisshowninT able4-1.
Table4-1PortRoleandPortState
PortrolePortstate
MasterForward
RootForward
DesignatedForward
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SJ-20120409144109-002|2012-07-02(R1.0)ZTEProprietaryandCondential