stp協(xié)議選舉規(guī)則

1、SW1disstpinterfaceEthernet0/0/1CISTGlobalInfoModeSTPCISTBridge:32760.4clf-cce9-4d89ConfigTimes:Hello2sMaxAge20sFwDly15sMaxHop20ActiveTimes:Hello2sMaxAge20sFwDly15sMaxHop20CISTRoot/ERPC:32760.4clf-cc30-66d6/1CISTRegRoot/lRPC:32760.4clf-cce9-4d89/0CISTRootPortld:128.4BPDU-Protection:DisabledTCorTCNrec

2、eived:45TCcountperhello:0STPConvergeMode:NormalTimesincelastTC:0daysOh:4m:36sNunLberofTC:9LastTCoccurred:EthernetO/0/4Portl(EthernetO/O/1)FORWARDINGPortProtocol:EnabledPortRole:DesignatedPortPortPriority:12SSW1disstpinterfaceEthernet0/0/4CISTGlobalInfcModeSTPCISTBridge:3276E.4clf-cce9-4d89ConfigTime

3、s:Helle2sMaxAge20sFwDly15sMaxHcp20ActiveTimes:Helle2sMdXAjge20sFwDly15sMdXHcp20CISTRoot/ERPC:3276E.4clf-cc30-6ed/1CISTRegRao七J工RPC:3276E：.4clf-cce9-4d89/0CISTRootPortld:123.4BPDU-Protection:DisabledTCorTCNreceived:45TCcountperhello:0STPConvergeMode:NormalTimesincelastTC:0daysOh.:5dcl:30sNdinberofTC:

4、9LastTC匚cu-ired:EthernetO/D/4Por七4(Eth.ern.etO/0/4FORWARDINGPortPre七門匚口1:Ena上ZLe已PortRole:RootPortPortPriority:129SW2displaystpinterfaceeO/0/11ISW2displaystpinterfacee/0/2CISTGlobalInfoModeSTP11CISTGlobalInfoModeSTPCISTBridge:32768.4clf-cc98-974cCISTBridge:32768.4clf-cc93-974cConfigTimes:Hello2sMaxA

5、ge20sFwDly15sMaxHop20ConfigTimes:Hello2sMaxAge20sFwDly15sMayHop20ActiveTimes:Hello2sMaxAge20sFwDly15sMaxHop20ActiveTinies:Hella2sMaxAge20sFwDly1EsMayHop20CISTRoot/ERPC:3276S.4clf-cc30-66d6/2CISTRoot/ERPCJ:32768.4clf-cc30-66dS/2CISTRegRoot/lRPC:3276S.4clf-cc98-974c/0CISTR&gRcot/IRPC:32768.4clf-cc93-9

6、74c/0CISTRootPortld:128.2CISTRootEor七工ci:123.2BPDU-Protection:DisabledBPDU-Pro七Eiution:DisabledTCorTCNreceived:119TCorTCN工已匚eived:113TCcountperhello:0TCcountperhello;0STPConvergeMode:NormalstpconvergeMede:iTormalTimesincelastTC:0daysOh.:6m:7sTimesin匚總lasttc:0-lays011：Bdcl:48sNuiriberofTC:10JNimibero

7、ftc:10LastTCoccurred:Ethernet0/0/2LastTCoccurred:Etjierr.e/U/2Portl(EthernetO/O/1)1DISCARDING11Ports(Ettiernet0/0/2)FORWARDIMGPortProtocol:Enabled1PortProtocol:EnabledPortRole:AlternatePort1PortRole:RootPortPortPriority:129|PartPriority:12SSW3displaystpinterfacee0/0/2Ir1TcT1r11Tn-F1IWcTrorpn1I|SW3di

8、splaystpinterfacee0/0/3ILxo丄丄匸iiuajLxnjzoiLno口巳ojlfjCISTGlobalInfaModeSTPCISTBridge:32768.4clf-cc62-8aa0CISTBridge:.clf-cc62-8aaBConfigTimes:Hello2sMaxAge20sFwDly15sMaxHop20ConfJgTimes:Helle2sMaxAg-e2)s瞰工L*15s20ActiveTimes:Hello2sMaxAge20sFwDly15sMaxHop20ActiveTimes:Helle2sMaxAge20sEWD1V15sMaxHop20C

9、ISTRoot/ERPC:32760.4clf-cc30-66d6/1CISTRoq/ERPC=3275.clf-cc30-66d6/1CISTRegRoot/IRPC:32769.4clf-cc62-8aa0/0CISTReg-RootZl?lPC:327B.clf-cc62-SaaB/0CISTRootPortld:120.3CISTRootPortld:12S.3BPDU-Protection:DisabledBPDU-Protection:Dish1edTCorTCNreceived:47TCorTCNreceived：47TCcountperhello:0TCcountperjiel

10、lo:0STPConvergeMode:NormalSTPConvergeMode:NarmalTimesincelastTC:0daysOh:10m:47sTimesincelastTC:0d=ysOh:Uhl:37sNumberofTC:11NuinberoETC:11LastTCoccurred:Ethernet0/0/3LastTCoccurred:Ethernet.0/0/3Port2(Ethernet0/0/2)FORWARDING1Por3CEtjiernetD/U/3)FORWAKDING一PortProtocol:EnabledPortProtocol:EnabledPort

11、Role:DesignatedPortPortRole:Roo七PortPortPriority:129PortPriori七y:128SW4disstpintSW4disstpinterfaceeO/0/3CISTGlobal:EnfoModeSTPCISTBridge:3276S.4clf-cc30-66d6ConfigTimes:Hello2sMaxAge20sFwDly15sMaxHop20ActiveTimes:Hello2sMaxAge20sFwDly15sMaxHop20CISTRoot/ERPC:3276S.4clf-cc30-66d6/0CISTRegRoot/lRPC:32

12、76S.4clf-cc30-66d6/0CISTRootPortld:0.0BPDU-Protection:DisabledTCorTCNreceived:12TCcountperhello:0STPConvergeMode:NormalTimesincelastTC:0daysOh:12m.:29sNumberofTC:10LastTCoccurred:Ethernet0/0/4Port3(Ethernet0/0/3)FORWARDINGPortProtocol:EnabledPortRole:DesignatedPortPortPriority:12SSW4disstpinterfacee

13、0/0/4CISTGlobalInfoModeSTPCISTBridge:32768.4clf-cc30-66d6ConfigTimes:Hello2sMaxAge2DsFwDly15sMaxHop20ActiveTimes:HslIo2eMaxAge2DeFwDly1EeMaxHop20CISTRoot/ERPC:32768.4clf-cc30-66d6/0CISTRegRoot/lRPC:32768.4clf-cc30-66d6/0CISTRootPortld:0.0BPDU-Protection.:DisabledTCorTCNreceived:12TCcoUnsperhello:0ST

14、PConvergeMode:NcrmalTimesincelastTC:0daysOh:14m:54sNuiriberofTC:10LastTCoccurred:EthernetO/0/4Port4(Ethernet0/0/4)FORWARDINGPortProtocol:EnabledPortRole:DesignatedPortPortPriority:1281選取根網(wǎng)橋（rootbridge）只選取一個根交換機1）比較交換機的BridgeID（16位優(yōu)先級+48位MAC）,取ID小的。優(yōu)先級可配，如果優(yōu)先級相同（默認是32768）,則比較MAC。選取根接口（rootport）每個非根交換

15、機上選取一個根接口1）先比較到達根網(wǎng)橋所經(jīng)過的所有交換機的出接口的cost值的總和。取cost總和值小的為根接口。2）當cost總和相同時，則比較對端交換機的BridgeID,取值小的為根接口3）當BridgeID也相同時，則比較對端PortiD，去小的為根接口。選取指定接口（DesignatedPort）每條鏈路上選取一個指定端口1）根網(wǎng)橋上的接口都是指定接口。2）比較該鏈路兩端的交換機到達根網(wǎng)橋所經(jīng)過的所有交換機的出接口的cost值的總和。取小的為指定端口。3）如果cost值的總和相同，則比較該條鏈路兩端的交換機BridgeID,取BridgeID小的上面的端口為指定端口。4）如果鏈路兩端交換機BridgeID也是相同，則比較對端接口的PortID（由接口優(yōu)先級和接口號構成，默認優(yōu)先級128），取小的為指定接口。4將其它非根、非指