Zte ZXR10 2900 Series - Table 13 Port Role and Port State

ZXR102900SeriesUserManual
portshavethesamecosttotherootbridge,thentheportwith
thelowestportprioritybecomestotherootport.
�Designated:Theporttransmitsdatatoswitchdownward,and
sendsSTPprotocolmessagetomaintainthestateofSTP .
�Backup:TheportreceivestheSTPmessage,whichprovesthat
thereexitsalooproutetotheportitself.
�Alternate:TheportreceivesexcessSTPprotocolmessagefrom
otherequipment.However ,whentheoriginallinkabnormally
lost,theportunderthisstatecantransfertotransmittingstate
andmaintainthenetworkinsteadoftheportlapsed.
�Edged:Theportisusedtoconnecttheterminalequipment,
suchasPC.Theportdoesnotparticipateincalculationbefore
STPisstable,andthestatecanbeswitchedfast.
Accordingtoportrole,thestateafterthecalculationbeingsteady
isshowninTable13.
TABLE13PORTROLEANDPORTSTATE
Portrole
Portstate
Master
Forward
Root
Forward
DesignatedForward
BackupDiscard
AlternateDiscard
EdgedForward
BPDUprotectfunctionisfortheprotectionofmarginport.The
marginportwillnotreceivetheprotocolmessage.Ifthereexists
viciousprotocolattackorLinuxvirtualbridge,receivingunlawful
protocolmessagewillbringtonetshockingortopologychanging
abnormally.Theportwillbeclosedafterusingtheprotection.
Afterawhile,tocheckthenetisnormalornot.Ifitisnormal,it
willrecovertooriginalstate.
Rootprotectionisfunctionisfortheprotectionofrootswitch.In
thenetworkthatneedstoappointswitchasrootswitch,ifthere
existsviciousprotocolattackorLinuxvirtualbridge,itwillbring
thechangetotherootandnetabnormal.Afterusingtheroot
protectionoftheport,iftheportreceivestheprotocolinformation
priortorootswitch,itwilltransfertheporttoblockingstate.This
portnolongertransmitsmessage,anddiscardsthereceivedpro-
tocolmessagetoprotectthestatusoftherootswitch.
Loopprotectionfunctionisfortheprotectionofloopnettopology.
Inthenetworkwhereringexists,redundanttopologywillbeinthe
stateofbackup,andinthestateofblockingaftertheportissteady.
Ifthereisnoneedtotransfertotransmissionstate,itispossible
tosetporttoloopprotect.Oncetheportwantstotransform,it
willinspireloopprotectionandsettheporttoblockingstate.
96CondentialandProprietaryInformationofZTECORPORATION