RSTP的收敛过程

1、RSTP 的收敛过程RSTP (IEEE 802.1 w)RSTP与标准STP(IEEE 802.1 D)的最主要区别是 RSTP不再依赖转发延迟的计时器(Forward Delay timer) o RSTP通过Proposal/Agreement机制缩短收 敛时间。根据RSTP的规则，如果连续三个BPDU丢失(默认6 秒)，则认为交换机之间的RSTP关系中断。较短的 失效时间便于更快的探测故障。标准STP有五个端口状态(Port State), RSTP缩减 为三个端口状态。RSTP BPDU冋ag FieldRSTP Version 2 BPDUFieldByteLengthProtoc

2、ol ID-OxOOOO2Protocol versionID= 0x021BPDU Type= 0x021Flag»1Root ID8Root Path Cost4Bridge ID8Port ID2Message Age2Max Age2Hello Time2Forward Delay2FieldBHLengthTopology Change7Proposal6Part Rote4-5Un known Part00Alternate or Backup Port01P#10Designated Port11Learning3Forwarding2AyrerncntiTopolog

3、y Change0AcknowledgementRSTP BPDU标志位Agreement 和 Root portRSTP BPDU标志位Proposal Topology ChangeLearning00 Unknownt t tTopology Change ACK AgreementForwarding01 Alternative/Backup 10 Root 8 L11 Designated!s Spanrring Tree ProtocolPTOtrocol IdaSpanningProtocol (0x0000)IProtocol ersion Tdentifier: Rapid

4、Sparining Tree I BPDU Type: Rapid/Multiple Spanning Tree (0x02) BPDU flags: OxOe (Port Role: Designated, Proposal) O= Tnpnlngy Chngp Arknow!pdgmpnt- Nc.0二 Agreement: No .0二 For warding: No二 Lia厂ning: No匚. 11 = Port Roia: DQsiqnatQcl (3) 匚7.I二 Proposal: Yes I 0= Topology Change: Noa Root Identifier:

5、32768 / 1 / 00:12:01:24:7d:80Root Path Cost: 0o Bridge Identifier: 32768 / 1 / 00:12:01:24:7d:80Port identifier: 0x8003wessaye Age: 0Max Age: 20Hello Time: 2Forward Delay: 15e Spanninq Tree ProtocolProtocol Identifier: Soannina Tree Protocol (0x0000)IProtoco1 Version Identifier: Raoid Spannin。Tree (

6、2)1BPDU Type; Rapid/Multiple Spanning Tree (0x02)q BPDU flags: 0x79 (Agreement, Forwarding, Learning, P0= Topology Change Acknowledqment: NoProposal 和 Designated port|1= Aq亡ei】i亡门t: Yes|1= Forwa厂ding: Yes.1 = Learnlna: ywsl l_0=Port Role: Root (2)10.= Proposal: No1= Topology Change: Yes0 Root Identi

7、fier: 32768 / 1 / 00:12:01:24:7d:80Root Path Cost: 190 Bridge Identifier: 32768 / 1 / 00:12:43:54:9e:00Port identifier: 0x8003Message Age: 0Max Age: 20Hello Time: 2Forward Delay: 15Agreement 和 Root portRSTP端口状态DiscardingForwardingLearningI g oSTP/RSTP收敛过程的三个步骤步骤1选根桥步骤2选根端口步骤3选指定端口7RSTP Proposal/Agre

8、ement过程所有交换机都运行RSTPPOST未完成BID=32,768.0000.0C11.1111P1P2POST已完成BID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPp4: designated portp6: designated portp6 port role: designated port no forwardi ng no learningBID=325768.0000.0C55.5555tl T>MPDU RID=BIDof B I Proposal1 p4 port role: design

9、ated port I P6no forwardingno learningBID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPBID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPPOST已完成BID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPPOST未完成BID=32,768.0000.0C11.1111RootRSTP Proposal/Agreement过程所有交换机都运行

10、RSTPRootRSTP Proposal/Agreement过程所有交换机都运行RSTPP1P2POST已完成RootRSTP Proposal/Agreement过程所有交换机都运行RSTPp3: alternate port p4: new root port p5: edge portp6: designated port2. sync (unchanged)Synchronization同步BID=325768.0000.0C55.5555你的BID比我的小！ 我承认你是根。.sync (unchanged)RootRSTP Proposal/Agreement过程所有交换机都运行R

11、STPp6POST已完成RootRSTP Proposal/Agreement过程所有交换机都运行RSTPBID=32,768.0000.0C22.2222RootRSTP Proposal/Agreement过程所有交换机都运行RSTPPOST未完成BID=32,768.0000.0C11.1111BID=32,768.0000.0C22.2222RootRSTP Proposal/Agreement过程所有交换机都运行RSTPBID=32,768.0000.0C22.2222RootRSTP Proposal/Agreement过程所有交换机都运行RSTPP1P2BID=32,768.00

12、00.0C22.2222RootRSTP Proposal/Agreement过程所有交换机都运行RSTPBID=32,768.0000.0C22.2222RootRSTP Proposal/Agreement过程所有交换机都运行RSTPPOST已完成BID=325768.0000.0C55.5555p3: alternate port p4: new root port p5: edge portp6: designated portBID=32,768.0000.0C22.2222RootRSTP Proposal/Agreement过程所有交换机都运行RSTP当p6收到Agreement

13、信息后，处于 forwarding 和 learning 状态。I SPDU RID=BID of CIAgreeme nt1 p4 port role: root portI P6 forwardinglear ningBID=32,768.0000.0C22.2222RootRSTP Proposal/Agreement过程所有交换机都运行RSTPBID=32,768.0000.0C22.2222RootRSTP Proposal/Agreement过程所有交换机都运行RSTPPOST已完成BID=32,768.0000.0C22.2222RootRSTP Proposal/Agreeme

14、nt过程所有交换机都运行RSTPPOST已完成BID=32,768.0000.0C11.1111p1: designated portp2: designated portRootRSTP Proposal/Agreement过程所有交换机都运行RSTPRootRSTP Proposal/Agreement过程所有交换机都运行RSTP1.BPDU RID=BID of C Proposalp2 port role: designated port no forwarding no learningPOST已尋成p4: root portp6: designated port1.BPDU RID

15、=BIDof A Proposalp1 port role: designated port no forwarding no learningBID=325768.0000.0C55.5555RootRSTP Proposal/Agreement过程所有交换机都运行RSTPRootRSTP Proposal/Agreement过程所有交换机都运行RSTPRPDPP6RootRSTP Proposal/Agreement过程所有交换机都运行RSTPRootRSTP Proposal/Agreement过程所有交换机都运行RSTPPOST已完成BID=32,768.0000.0C22.2222R

16、ootRSTP Proposal/Agreement过程所有交换机都运行RSTPRootRootRSTP Proposal/Agreement过程所有交换机都运行RSTPRootRSTP Proposal/Agreement过程所有交换机都运行RSTPBID=32,768.0000.0C11.1111p1: designated port p2: new root portRootRSTP Proposal/Agreement过程所有交换机都运行RSTPRootRSTP Proposal/Agreement过程所有交换机都运行RSTPP2当p1收到Agreement信息后，处于forwardi

17、ng 和 learning 状态。3. BPDU RID=BIDof A Agreeme ntp2 port role: root port forwarding lear ning你的BID比当前的RID小! 我承认你是根。.RootRSTP Proposal/Agreement过程所有交换机都运行RSTPBID=325768.0000.0C55.5555RootRSTP Proposal/Agreement过程所有交换机都运行RSTPRootRSTP Proposal/Agreement过程所有交换机都运行RSTP2.sync (unchanged).P42. sync (block)2.

18、 sync (unchanged)RootRSTP Proposal/Agreement过程所有交换机都运行RSTPRootRSTP Proposal/Agreement过程所有交换机都运行RSTPDP I P6p3: alternate port p4: designated port p5: edge portp6: designated portBID=32,768.0000.0C22.2222RootRSTP Proposal/Agreement过程所有交换机都运行RSTPRootp1: designated port p2: root portBID=32,768.0000.0C11

19、.1111P1P2p3: alternate port p4: designated port p5: edge portp6: designated portP6BID=325768.0000.0C55.5555PDU RID=BIDof AProposalort role: designated port no forwardi ng no learningBID=32,768.0000.0C22.2222RootRSTP Proposal/Agreement过程所有交换机都运行RSTPRootp1: designated port p2: root portBID=32,768.0000

20、.0C11.1111P1P2BID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPBID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTP当p4收到Agreement信息后，处于forwarding 和 learning 状态。BID=325768.0000.0C55.5555lear ningp3: alternate port p4: designated port p5: edge port p6: new root portP6你的RID比我的小!

21、我承认A是根。5. BPDU RID=BID ofAgreeme nt p6 port role: root portforwardingBID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPRootp1: designated port p2: root portBID=32,768.0000.0C11.1111DPP1RPP2BID=325768.0000.0C55.5555RPp3: alternate port p4: designated port p5: edge port p6: root portBID=32

22、,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPRootBID=32,768.0000.0C11.1111P7Ap8p7: designated port p8: designated portRID=1.BPDU RID=BID of D ProposalNew linkp8 port role: designated port Rn no forwarding no learningP1BID=325768.0000.0C33.3333roposalport role: designated port no forwardi

23、ng no learningP2P6p1: designated port p2: root port p3: alternate port p4: designated port p5: edge port p6: root portBID=325768.0000.0C55.5555BID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程BID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程Root所有交换机都运行RSTP当P7收到Agreement信息后，处于 forwarding 和 learnin

24、g 状态。2. BPDU RID=BIDof D一Agreeme ntp8 port role: root forwarding lear ning你的BID比我的小！ 我承认你是根。pxp8，ZBID=325768.0000.0C33.3333P7P1BID=32,768.0000.0C11.1111p7: designated port p8: new root portP2p1: designated port p2: root port p3: alternate port p4: designated port p5: edge port p6: root portBID=32576

25、8.0000.0C55.5555P6BID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程RSTP Proposal/Agreement过程RootBID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPBID=325768.0000.0C33.3333RootBID=32,768.0000.0C11.1111P1p1: designated port p2: root portCost = 19 p3: alternate port?p4: designated portPp5:

26、 edge portp6: root portBID=325768.0000.0C55.55551. BPDU RID=BIDof A、Proposal上p10 port role: designated p no forwardi ng no learningPath Cost=19Sender BID = BID ofCost = 19P6BPDU RID=BIDof APath Cost=19Sender BID = BID of BD、1. BPDU RID=BID of A Proposalp9 port role: desig mated port no forwardi ng n

27、o learningPath Cost=38Sender BID = BID of CP9BID=32,768.0000.0C22.2222p9: designated portp10: designated portRSTP Proposal/Agreement过程所有交换机都运行RSTPRootBID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPP1BID=325768.0000.0C33.3333BID=32,768.0000.0C11.1111p1: designated port p2: root port p3

28、: alternate port p4: designated port p5: edge port p6: alternate portBID=325768.0000.0C55.5555BID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPBID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPPWDPCost = 19Cost = 19BID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RS

29、TPBID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPP6New linkBID=32,768.0000.0C22.2222RSTP Proposal/Agreement过程所有交换机都运行RSTPP92. BPDU Sender BID DPath Cost=19+ 19 = 382. BPDU Sender BID BP9的Path Cost值与p6的相同。 D交换机的Sender BID比B的小。Path Cost=19 + 19 = 38BID=32,768.0000.0C22.2222RSTP Proposal

30、/Agreement过程所有交换机都运行RSTPBID=325768.0000.0C33.3333RootP1BID=32,768.0000.0C11.1111p1: designated port p2: root portCost = 19 p3: alternate portp4: designated port p5: edge port p6: alternate portBID=325768.0000.0C55.5555P1Cost = 19Cost = 19New linkP6NDPRPp9BID=32,768.0000.0C22.2222p9: new root portp10

31、: designated portRSTP Proposal/Agreement过程所有交换机都运行RSTPRootRPp9BID=32,768.0000.0C22.2222p9: new root portp10: designated portRSTP Proposal/Agreement过程所有交换机都运行RSTPRPp9BID=32,768.0000.0C22.2222p9: new root portp10: designated portRSTP Proposal/Agreement过程所有交换机都运行RSTPP1Cost = 19 p3: alternate portBID=32

32、5768.0000.0C33.3333BID=32,768.0000.0C11.1111p1: designated port p2: root portp4: designated port p5: edge port p6: alternate portBID=325768.0000.0C55.5555RPp9BID=32,768.0000.0C22.2222p9: new root portp10: designated portRSTP Proposal/Agreement过程所有交换机都运行RSTPRPp9BID=32,768.0000.0C22.2222p9: new root p

33、ortp10: designated portRSTP Proposal/Agreement过程所有交换机都运行RSTPPlCost = 19Cost = 19当p10收到Agreement信息后，处于forwarding 和 learning 状态。New linkP6NDPRPp9BID=32,768.0000.0C22.2222p9: new root portp10: designated portRSTP Proposal/Agreement过程所有交换机都运行RSTPRPp9BID=32,768.0000.0C22.2222p9: new root portp10: designa

34、ted portRSTP Proposal/Agreement过程所有交换机都运行RSTP3. BPDU RID=BIDof A Agreeme ntp9 port role: root port forwarding lear ningRPp9BID=32,768.0000.0C22.2222p9: new root portp10: designated portRSTP Proposal/Agreement过程所有交换机都运行RSTPBID=325768.0000.0C33.3333p1: designated port p2: root port p3: alternate port

35、p4: designated port p5: edge port p6: alternate port p7: designated port p8: root port p9: root port p10: designated portRootPDPCost = 19DPRPBID=32,768.0000.0C11.1111P1Cost = 19P2DPCost = 19NDPp6BID=325768.0000.0C55.5555RPp9BID=32,768.0000.0C22.2222RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPRootBID=32,

36、768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPDP I p1Cost = 19BID=32,768.0000.0C11.1111BID=325768.0000.0C55.5555p1: designated port p2: root port p3: alternate port p4: desi

37、gnated port p5: edge port p6: alternate port p7: designated port p8: root port p9: root port p10: designated portBID=32,768.0000.0C33.3333BID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C

38、,D运行RSTPSWE运行标准STP1.BPDU(ver 2) RID=BID of A P11ProposalIp11 port role: designated port Ino forwarding1no learningDPNew linkNDPp6P91ODPCost = 1912SWE标准STPBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPRootp1: designated port p2: root port p3: alternate port

39、 p4: designated port p5: edge port p6: alternate port p7: designated port p8: root port p9: root port p10: designated portBID=32,768.0000.0C33.3333Cost = 191.BPDU(ver 2) RID=BID of A P11Proposalp11 port role: designated portIno forwardi ngIno learningw我看不懂你的信息!DPp7DPNew linkNDPp6p91ODPCost = 19BID=3

40、2,768.0000.0C11.1111BID=325768.0000.0C55.555512SWE标准STPBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPRootBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的

41、互操作交换机A,B,C,D运行RSTPSWE运行标准STPDP I p1Cost = 19BID=32,768.0000.0C11.1111BID=325768.0000.0C55.5555p1: designated port p2: root port p3: alternate port p4: designated port p5: edge port p6: alternate port p7: designated port p8: root port p9: root port p10: designated port2. p11 noforwarding等待BPDU3. BPD

42、U RID=BID of (ver 0) p12 listeningtSWE IP11DPNew linkNDPp6P91ODPCost = 19SWE12标准STPBID=32,768.0000.0C33.3333BID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPRootDP I p1Cost = 19BID=32,768.0000.0C11.1111BID=325768.0000.0C55.5555p1: designated port p2: root por

43、t p3: alternate port p4: designated port p5: edge port p6: alternate port p7: designated port p8: root port p9: root port p10: designated port4.哦，你的BPDU版本 P11 号是0,你运行的是 标准的STP o3. BPDU RID=BID of (ver 0) p12 listeningtSWEDPNDPp6p91ODPNew linkCost = 19SWE12标准STPBID=32,768.0000.0C33.3333BID=32,768.000

44、0.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPRootDP I p1Cost = 19BID=32,768.0000.0C11.1111BID=325768.0000.0C55.5555p1: designated port p2: root port p3: alternate port p4: designated port p5: edge port p6: alternate port p7: designated port p8: root port p9: root port

45、p10: designated portBID=32,768.0000.0C33.3333BID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPp115. BPDU RID=BID ofAi(ver 0)Ip11 listening1DPNew linkNDPp6P91ODPCost = 19

46、12SWE标准STPBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPRootp1: designated port p2: root port p3: alternate port p4: designated port p5: edge port p6: alternate port p7: designated port p8: root port p9: root port p10: designated portBID=32,768.0000.0C33.3

47、333Cost = 19P115. BPDU RID=BID of A(ver 0)Ip11 listeningDPp7DPNew linkNDPp6P91ODPRPCost = 19BID=32,768.0000.0C11.1111BID=325768.0000.0C55.5555SWE你的RID比我的小! 我承认A是根。.12标准STPBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPRootp1: designated port p2: root port p

48、3: alternate port p4: designated port p5: edge port p6: alternate port p7: designated port p8: root port p9: root port p10: designated portBID=32,768.0000.0C33.3333DP I P1Cost = 19BID=32,768.0000.0C11.1111BID=325768.0000.0C55.5555P11 和 p12 在两个 forward-delay 间隔内不能转发用户数据。 它们遵守标准STP的规则。DPNDPp612标准STPSW

49、E1ODPP11DPCost = 19BID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPRootBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPBID=32,768.0000.0C22.2222BID=32,768.0000.0C66.6666RSTP与标准STP的互操作交换机A,B,C,D运行RSTPSWE运行标准STPDP I p1Cost = 19BID=32,768.000