H3C交换机与Cisco交换机STP协议对接注意事项
思科H3C交换机生成树对接问题解决方法
MSTP--多生成树协议/MiniSite/H3care_Club/Data_Center/Net_Reptile/The_One/Home/Catalog/200911/655244_97665_0.htm作者：| 上传时间：2009-11-16 | TAG：前面提到的STP/RSTP协议以及Cisco的私有协议PVST+都属于单生成树（SST）协议，也就是对于支持多vlan的设备只能运行单一的生成树。
MSTP是IEEE 802.1s中提出的一种STP和VLAN结合使用的新协议，它既继承了RSTP端口快速迁移的优点，又解决了RSTP中不同vlan必须运行在同一棵生成树上的问题。
接下来我们从MSTP基本概念、基本原理、报文特征、H3C产品实现以及与Cisco产品互通等几个方面进行阐述，在总结中引入了H3C设备为了应对实际网络环境所提供的特定保护功能，在附录中是MSTP模块的缺省配置。
1MSTP基本概念图1 MSTP基本概念示意图实例和域多生成树协议MSTP（Multiple Spanning Tree Protocol）是IEEE 802.1s中定义的一种新型生成树协议。
简单说来，STP/RSTP是基于端口的，PVST＋是基于VLAN的，而MSTP 是基于实例的。
与STP/RSTP和PVST+相比，MSTP中引入了“实例”（Instance）和“域”(Region) “的概念。
所谓“实例”就是多个VLAN的一个集合，这种通过多个VLAN捆绑到一个实例中去的方法可以节省通信开销和资源占用率。
MSTP各个实例拓扑的计算是独立的，在这些实例上就可以实现负载均衡。
使用的时候，可以把多个相同拓扑结构的VLAN 映射到某一个实例中，这些VLAN在端口上的转发状态将取决于对应实例在MSTP里的转发状态。
所谓“域”，由域名(Configuration Name)、修订级别(Revision Level)、格式选择器(Configuration Identifier Format Selector[1])、VLAN与实例的映射关系(mapping of VIDs to spanning trees)，其中域名、格式选择器和修订级别在BPDU报文中都有相关字段，而VLAN 与实例的映射关系在BPDU报文中表现摘要信息(Configuration Digest)，该摘要是根据映射关系计算得到的一个16字节签名。
Cisco交换机之STP协议简单详解
Cisco交换机之STP协议简单详解及实验Cisco交换机之STP协议简单详解及实验前面的学习中,我们已经掌握通过交换机组网,但是,怎样加强企业网络的可靠性呢?在实际网络环境中,可以通过物理环路解决网络的可靠性,当一跳链路断开或者出现故障,另一条链路任然可以传输数据,但是,在交换网络中,当交换机收到一个未知目的地址的数据帧,交换机会广播出去,这样,在交换网络中,就会产生一个双向广播环,甚至广播风暴,导致交换机死机。
本章的STP(Spanning Tree Protocol 生成树协议),它就是在逻辑上断开物理环路,防止产生广播风暴,而一旦正在用的线路出现故障,被逻辑断开的线路又重新接通,继续传输数据。
在介绍STP之前,首先回顾一下交换机的工作原理(1)交换机通过学习数据帧中的源MAC地址生成MAC地址表。
(2)交换机查看数据帧的目标MAC地址,根据MAC地址表转发数据。
(3)如果交换机MAC地址表中没有匹配项,则向除了收到这个数据帧的端口以外的所有端口广播这个数据帧。
如果在一个物理环路的网络中,交换机收到一个未知目标地址的数据帧,它会向其他交换机广播,而其他交换机也没有相应的MAC地址对应,又会向除接受端口之外的端口广播,这样,在网络中就产生了双向广播环。
一.STP概述1.STP叫做生成树协议,就是把一个环形的结构改变成一个树形的结构二.STP工作原理 1.生成树算法(1)选择根网桥(Root Bridge)选择根网桥的依据是网桥ID(8字节的字段)前2字节为网桥优先级(范围是0--65535,默认值是32768),后6字节是网桥的MAC地址。
(2)选择根端口(Root Ports)选择根端口的依据按照顺序是:到根网桥最底的根路径成本直连的网桥ID最小端口ID最小下面是带宽与路径成本的关系链路带宽(Mb/s)路径成本10 10016 6245 39100 19155 14622 61000 410000 2端口ID是一个2字节的STP参数,前8位是端口优先级(范围是0--255,默认是128)后8位是端口编号,注意:端口编号不是端口号,但是端口号低的端口,端口编号值也较小。
STP协议详解及跨厂商互通指导
18
局域网设计举例
19
设计原则
可靠、冗余以及易管理是设计的三大原则，具体如下：
1、如果维护力量有限，且局域网带宽充裕，采用默认的MSTP，但不进行多实例的 划分； 2、在连接终端的交换机端口的防环路技术上，鉴于不同低端交换机对loopbackdetection检测出环路的处理机制不同，不利管理，采用边缘端口+BPDU 保护； 3、在接入交换机和核心之间的防止链路单通的技术上，由于交换机形态多，不采 用DLDP，采用stp loop-protection技术； 4、两台核心交换机下连接入交换机的端口采用stp root-protection； 5、所有接入交换机的下连端口设置广播抑制比5%，核心的抑制比设置为10%。
STP功能关闭，端口环回。
7
Loop-protection
Layer2 network
链路单通，单项 链路单通，单项BPDU 报文丢失，导致环路。 报文丢失，导致环路。 RP AP 以太网接口视图下配置： 以太网接口视图下配置： Stp loop-protection
8
DLDP-单通故障检测 单通故障检测
H3C交换机和 交换机和cisco交换机的 互通 交换机的stp互通 交换机和 交换机的
STP协议与PVST+协议只能在VLAN 1内进行互通 RSTP协议与Rapid-PVST+协议只能在VLAN 1内进行互通，并保证整个 网络所有VLAN使用一棵生成树。 ●默认情况下，由于摘要信息不同，MSTP协议与MST协议只能进行域间互 通（要完成MSTP域内互通，则必须要在连接Cisco交换机的H3C交换机 上，以及连接Cisco交换机的H3C交换机的端口上使能“摘要侦听”功 能）
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H3C STP配置要点以及注意事项
当RoodID,Cost相同，交换机MAC大的端口为Discarding端口。
如果，RoodID,Cost，DesignatedBridgeID相同，说明是两个交换机间有两根以上的线相连。
Port Role :CIST Designated Port
Port Priority :128
Port Cost(Legacy) :Config=auto / Active=200
Desg. Bridge/Port :0.000f-e28c-f2c7 / 128.1
在对一个端口进行配置的时候，在Loop保护功能，Root保护功能或者边缘端口设置三个配置中，同一时刻只能有一个配置生效。
缺省情况下，交换机不启动BPDU保护功能、Root保护功能和环路保护功能。
总之，直接与终端相连的端口设为边缘端口,根交换机设为Root保护功能，次汇聚交换机设为环路保护功能。
根交换机的Hello Time、Forward Delay以及Maximum Age三个时间参数取值之间应该满足如下公式，否则网络会频繁震荡：
2 × (forward-delay －1 second) >= mello time+ 1 second)
缺省情况下，交换机所有以太网端口均被配置为非边缘端口。
配置交换机的保护功能：
支持MSTP的交换机提供BPDU保护功能、Root保护功能和环路保护功能。
对于接入层设备，接入端口一般直接与用户终端（如PC机）或文件服务器相连，此时接入端口被设置为边缘端口以实现这些端口的快速迁移；当这些端口接收到配置消息（BPDU报文）时系统会自动将这些端口设置为非边缘端口，重新计算生成树，引起网络拓扑的震荡。这些端口正常情况下应该不会收到生成树协议的配置消息。如果有人伪造配置消息恶意攻击交换机，就会引起网络震荡。BPDU保护功能可以防止这种网络攻击。
H3C_STP_RSTP_MSTP协议原理及配置
Root Switch is 0001 Lowest Cost to Root = 7
Switch A BID =0001
Root Switch is 0001 Lowest Cost to Root = 3
Cost to Root =18 Switch B BID =0050 Cost to Root =7
Switch A BID =0001
Root Switch is 0001 Lowest Cost to Root = 3
Cost to Root =18 Switch B BID =0050 Cost to Root =7
Cost to Root =3 Switch C BID =1045 Cost to Root =22
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如何确定根桥
I’m the Root Switch
I’m the Root Switch
Switch A BID =0001
I’m the Root Switch
Switch B BID =0050
Switch C BID =1045
Switch D BID =0030
I’m the Root Switch
Root Switch = 0001 Lowest Cost to Root = 11
22
BPDU交换过程
I’m the Root Switch Lowest Cost to Root = 0
Root Switch is 0001 Lowest Cost to Root = 7
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如何确定根桥
I’m the Root Switch
Root Switch =0001
Switch A BID =0001
CISCO交换机STP详细说明及配置
CISCO交换机STP详细说明及配置一、STP概述STP（生成树协议）是一个二层管理协议。
在一个扩展的局域网中参与STP的所有交换机之间通过交换桥协议数据单元bp du（bridge protoc ol data unit）来实现；为稳定的生成树拓扑结构选择一个根桥；为每个交换网段选择一台指定交换机；将冗余路径上的交换机置为blocking，来消除网络中的环路。
IEEE 802.1d是最早关于STP的标准，它提供了网络的动态冗余切换机制。
STP使您能在网络设计中部署备份线路，并且保证：* 在主线路正常工作时，备份线路是关闭的。
* 当主线路出现故障时自动使能备份线路，切换数据流。
rSTP（rapidspanni ng tree protoc ol）是STP的扩展，其主要特点是增加了端口状态快速切换的机制，能够实现网络拓扑的快速转换。
1.1 设置STP模式使用命令configspanni ng-tree mode可以设置STP模式为802.1d STP或者802.1w rSTP.1.2 配置STP交换机中默认存在一个d efaul t STP域。
多域STP是扩展的802.1d，它允许在同一台交换设备上同时存在多个STP域，各个STP域都按照802.1d运行，各域之间互不影响。
它提供了一种能够更为灵活和稳定网络环境，基本实现在v l an中计算生成树。
1.2.1 创建或删除S T P利用命令createSTPd和d elete STPd可以创建或删除S TP.缺省的defaultSTP域不能手工创建和删除。
1.2.2 使能或关闭S T P交换机中ST P缺省状态是关闭的。
利用命令configSTPd可以使能或关闭S TP.1.2.3 使能或关闭指定STP的端口交换机中所有端口默认都是参与ST P计算的。
CISCO与H3CSTP对接检验测试
CISCO 与H3C STP对接测试实验拓扑一：H3C 3600-1配置：stp instance 1 priority 4096stp instance 2 priority 8192stp enablestp region-configurationregion-name Srevision-level 1instance 1 vlan 110 120instance 2 vlan 130 140active region-configurationstp config-digest-snoopingH3C 3600-2配置：stp instance 1 priority 8192stp instance 2 priority 4096stp enablestp region-configurationregion-name Sinstance 1 vlan 110 120instance 2 vlan 130 140active region-configurationstp config-digest-snoopingCISCO 3560配置：spanning-tree mode mstspanning-tree extend system-id!spanning-tree mst configurationname Srevision 1instance 1 vlan 110, 120instance 2 vlan 130, 140SPANNING-TREE 状态：H3C-3600-1：<h3c-1>dis stp briMSTID Port Role STP State Protection0 Ethernet1/0/1 ROOT FORW ARDING NONE0 Ethernet1/0/2 DESI FORWARDING NONE1 Ethernet1/0/1 DESI FORWARDING NONE1 Ethernet1/0/2 DESI FORWARDING NONE2 Ethernet1/0/1 ROOT FORWARDING NONE2 Ethernet1/0/2 DESI FORWARDING NONE (*) means port in aggregation group<h3c-1>dis stp ins 1-------[MSTI 1 Global Info]-------MSTI Bridge ID :4097.000f-e268-4df2MSTI RegRoot/IRPC :4097.000f-e268-4df2 / 0MSTI RootPortId :0.0Master Bridge :32768.000f-e268-4d14Cost to Master :200TC or TCN received :330----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4097.000f-e268-4df2 / 128.1Num of Vlans Mapped :2Rapid Fwd State :Rapid ForwardingPort Times :RemHops 20----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4097.000f-e268-4df2 / 128.2Num of Vlans Mapped :2Rapid Fwd State :Rapid ForwardingPort Times :RemHops 20<h3c-1>dis stp ins 2-------[MSTI 2 Global Info]-------MSTI Bridge ID :8194.000f-e268-4df2MSTI RegRoot/IRPC :4098.000f-e268-4d14 / 200MSTI RootPortId :128.1Master Bridge :32768.000f-e268-4d14Cost to Master :200TC or TCN received :191----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Role :Root PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4098.000f-e268-4d14 / 128.1Num of Vlans Mapped :2Port Times :RemHops 20----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :8194.000f-e268-4df2 / 128.2Num of Vlans Mapped :2Rapid Fwd State :Rapid ForwardingPort Times :RemHops 19----[Port5(Ethernet1/0/5)][DOWN]----Port Role :Disabled PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200000Desg. Bridge/Port :8194.000f-e268-4df2 / 128.5Num of Vlans Mapped :1Port Times :RemHops 20<h3c-1>dis stp ins 0-------[CIST Global Info][Mode MSTP]-------CIST Bridge :32768.000f-e268-4df2Bridge Times :Hello 2s MaxAge 20s FwDly 15s MaxHop 20 CIST Root/ERPC :32768.000f-e268-4d14 / 0CIST RegRoot/IRPC :32768.000f-e268-4d14 / 200CIST RootPortId :128.1BPDU-Protection :disabledTC-Protection :enabled / Threshold=6Bridge ConfigDigest Snooping :enabledTC or TCN received :344Time since last TC :0 days 0h:43m:8s----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Protocol :enabledPort Role :CIST Root PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :32768.000f-e268-4d14 / 128.1Port Edged :Config=disabled / Active=disabledPoint-to-point :Config=auto / Active=trueTransmit Limit :10 packets/hello-timeProtection Type :NoneMSTP BPDU format :Config=auto / Active=legacyPort ConfigDigest Snooping :disabledNum of Vlans Mapped :1PortTimes :Hello 2s MaxAge 20s FwDly 15s MsgAge 0s RemHop 20 BPDU Sent :2074TCN: 0, Config: 0, RST: 0, MST: 2074BPDU Received :2336TCN: 0, Config: 0, RST: 0, MST: 2336----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Protocol :enabledPort Role :CIST Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :32768.000f-e268-4df2 / 128.2Port Edged :Config=disabled / Active=disabledPoint-to-point :Config=auto / Active=trueTransmit Limit :10 packets/hello-timeProtection Type :NoneMSTP BPDU format :Config=auto / Active=standard(802.1s)Port ConfigDigest Snooping :enabledRapid Fwd State :Rapid ForwardingNum of Vlans Mapped :1PortTimes :Hello 2s MaxAge 20s FwDly 15s MsgAge 0s RemHop 19 BPDU Sent :1331TCN: 0, Config: 0, RST: 0, MST: 1331BPDU Received :13TCN: 0, Config: 0, RST: 0, MST: 13H3C-3600-2：<h3c-2>dis stp briMSTID Port Role STP State Protection0 Ethernet1/0/1 DESI FORWARDING NONE0 Ethernet1/0/2 DESI FORWARDING NONE1 Ethernet1/0/1 ROOT FORWARDING NONE1 Ethernet1/0/2 DESI FORWARDING NONE2 Ethernet1/0/1 DESI FORWARDING NONE2 Ethernet1/0/2 DESI FORWARDING NONE <h3c-2>dis stp ins 1-------[MSTI 1 Global Info]-------MSTI Bridge ID :8193.000f-e268-4d14MSTI RegRoot/IRPC :4097.000f-e268-4df2 / 200MSTI RootPortId :128.1Master Bridge :32768.000f-e268-4d14Cost to Master :0TC or TCN received :100----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Role :Root PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4097.000f-e268-4df2 / 128.1Num of Vlans Mapped :2Port Times :RemHops 20----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :8193.000f-e268-4d14 / 128.2Num of Vlans Mapped :2Port Times :RemHops 19<h3c-2>dis stp ins 1-------[MSTI 1 Global Info]-------MSTI Bridge ID :8193.000f-e268-4d14MSTI RegRoot/IRPC :4097.000f-e268-4df2 / 200MSTI RootPortId :128.1Master Bridge :32768.000f-e268-4d14Cost to Master :0TC or TCN received :100----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Role :Root PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4097.000f-e268-4df2 / 128.1Num of Vlans Mapped :2Port Times :RemHops 20----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :8193.000f-e268-4d14 / 128.2Num of Vlans Mapped :2Port Times :RemHops 19<h3c-2>dis stp ins 2-------[MSTI 2 Global Info]-------MSTI Bridge ID :4098.000f-e268-4d14MSTI RegRoot/IRPC :4098.000f-e268-4d14 / 0MSTI RootPortId :0.0Master Bridge :32768.000f-e268-4d14Cost to Master :0TC or TCN received :92----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4098.000f-e268-4d14 / 128.1Num of Vlans Mapped :2Port Times :RemHops 20----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4098.000f-e268-4d14 / 128.2Num of Vlans Mapped :2Port Times :RemHops 20<h3c-2>dis stp ins 0-------[CIST Global Info][Mode MSTP]-------CIST Bridge :32768.000f-e268-4d14Bridge Times :Hello 2s MaxAge 20s FwDly 15s MaxHop 20CIST Root/ERPC :32768.000f-e268-4d14 / 0CIST RegRoot/IRPC :32768.000f-e268-4d14 / 0CIST RootPortId :0.0BPDU-Protection :disabledTC-Protection :enabled / Threshold=6Bridge ConfigDigest Snooping :enabledTC or TCN received :278Time since last TC :0 days 0h:46m:51s----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Protocol :enabledPort Role :CIST Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :32768.000f-e268-4d14 / 128.1Port Edged :Config=disabled / Active=disabledPoint-to-point :Config=auto / Active=trueTransmit Limit :10 packets/hello-timeProtection Type :NoneMSTP BPDU format :Config=legacyPort ConfigDigest Snooping :disabledNum of Vlans Mapped :1PortTimes :Hello 2s MaxAge 20s FwDly 15s MsgAge 0s RemHop 20 BPDU Sent :2456TCN: 0, Config: 0, RST: 0, MST: 2456BPDU Received :2186TCN: 0, Config: 0, RST: 0, MST: 2186----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Protocol :enabledPort Role :CIST Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :32768.000f-e268-4d14 / 128.2Port Edged :Config=disabled / Active=disabledPoint-to-point :Config=auto / Active=trueTransmit Limit :10 packets/hello-timeProtection Type :NoneMSTP BPDU format :Config=legacyPort ConfigDigest Snooping :enabledNum of Vlans Mapped :1PortTimes :Hello 2s MaxAge 20s FwDly 15s MsgAge 0s RemHop 20 BPDU Sent :1436TCN: 0, Config: 0, RST: 0, MST: 1436BPDU Received :8TCN: 0, Config: 0, RST: 0, MST: 8CISCO 3560状态：Switch#sh spanning-tree mst 1 de##### MST1 vlans mapped: 110,120Bridge address d057.4c2c.a400 priority 32769 (32768 sysid 1)Root address 000f.e268.4df2 priority 4097 (4096 sysid 1)port Fa0/21 cost 200000 rem hops 19 FastEthernet0/21 of MST1 is root forwardingPort info port id 128.23 priority 128 cost 200000 Designated root address 000f.e268.4df2 priority 4097 cost 0 Designated bridge address 000f.e268.4df2 priority 4097 port id 128.2 Timers: message expires in 4 sec, forward delay 0, forward transitions 2Bpdus (MRecords) sent 20, received 1584FastEthernet0/22 of MST1 is alternate blockingPort info port id 128.24 priority 128 cost 200000 Designated root address 000f.e268.4df2 priority 4097 cost 200 Designated bridge address 000f.e268.4d14 priority 8193 port id 128.2 Timers: message expires in 4 sec, forward delay 0, forward transitions 0Bpdus (MRecords) sent 7, received 12Switch#sh spanning-tree mst 2 de##### MST2 vlans mapped: 130,140Bridge address d057.4c2c.a400 priority 32770 (32768 sysid 2)Root address 000f.e268.4d14 priority 4098 (4096 sysid 2)port Fa0/22 cost 200000 rem hops 19 FastEthernet0/21 of MST2 is alternate blockingPort info port id 128.23 priority 128 cost 200000 Designated root address 000f.e268.4d14 priority 4098 cost 200 Designated bridge address 000f.e268.4df2 priority 8194 port id 128.2 Timers: message expires in 4 sec, forward delay 0, forward transitions 1Bpdus (MRecords) sent 20, received 1589FastEthernet0/22 of MST2 is root forwardingPort info port id 128.24 priority 128 cost 200000 Designated root address 000f.e268.4d14 priority 4098 cost 0 Designated bridge address 000f.e268.4d14 priority 4098 port id 128.2 Timers: message expires in 4 sec, forward delay 0, forward transitions 1Bpdus (MRecords) sent 7, received 16Switch#sh spanning-tree mst 0 de##### MST0 vlans mapped: 1-109,111-119,121-129,131-139,141-4094Bridge address d057.4c2c.a400 priority 32768 (32768 sysid 0)Root address 000f.e268.4d14 priority 32768 (32768 sysid 0)port Fa0/22 path cost 0Regional Root address 000f.e268.4d14 priority 32768 (32768 sysid 0)internal cost 200000 rem hops 19 Operational hello time 2 , forward delay 15, max age 20, txholdcount 6Configured hello time 2 , forward delay 15, max age 20, max hops 20 FastEthernet0/21 of MST0 is alternate blockingPort info port id 128.23 priority 128 cost 200000 Designated root address 000f.e268.4d14 priority 32768 cost 0 Design. regional root address 000f.e268.4d14 priority 32768 cost 200 Designated bridge address 000f.e268.4df2 priority 32768 port id 128.2 Timers: message expires in 5 sec, forward delay 0, forward transitions 1Bpdus sent 20, received 1613FastEthernet0/22 of MST0 is root forwardingPort info port id 128.24 priority 128 cost 200000 Designated root address 000f.e268.4d14 priority 32768 cost 0 Design. regional root address 000f.e268.4d14 priority 32768 cost 0 Designated bridge address 000f.e268.4d14 priority 32768 port id 128.2 Timers: message expires in 5 sec, forward delay 0, forward transitions 1Bpdus sent 7, received 40实验拓扑二：CISCO 3550配置：spanning-tree mode mstspanning-tree extend system-id!spanning-tree mst configurationname Srevision 1instance 1 vlan 110, 120instance 2 vlan 130, 140SPANNING-TREE 状态：SW2#sh spanning-tree mst 1 de###### MST01 vlans mapped: 110,120Bridge address 0014.a897.e880 priority 32769 (32768 sysid 1)Root address 000f.e268.4df2 priority 4097 (4096 sysid 1)port Fa0/46 cost 400000 rem hops 18 FastEthernet0/46 of MST01 is root forwardingPort info port id 128.46 priority 128 cost 200000 Designated root address 000f.e268.4df2 priority 4097 cost 200000 Designated bridge address d057.4c2c.a400 priority 32769 port id 128.25 Timers: message expires in 5 sec, forward delay 0, forward transitions 1Bpdus (MRecords) sent 5, received 126SW2#sh spanning-tree mst 2 de###### MST02 vlans mapped: 130,140Bridge address 0014.a897.e880 priority 32770 (32768 sysid 2)Root address 000f.e268.4d14 priority 4098 (4096 sysid 2)port Fa0/46 cost 400000 rem hops 18 FastEthernet0/46 of MST02 is root forwardingPort info port id 128.46 priority 128 cost 200000 Designated root address 000f.e268.4d14 priority 4098 cost 200000 Designated bridge address d057.4c2c.a400 priority 32770 port id 128.25 Timers: message expires in 4 sec, forward delay 0, forward transitions 1Bpdus (MRecords) sent 5, received 128SW2#sh spanning-tree mst 0 de###### MST00 vlans mapped: 1-109,111-119,121-129,131-139,141-4094 Bridge address 0014.a897.e880 priority 32768 (32768 sysid 0)Root address 000f.e268.4d14 priority 32768 (32768 sysid 0)port Fa0/46 path cost 0IST master address 000f.e268.4d14 priority 32768 (32768 sysid 0)path cost 400000 rem hops 18 Operational hello time 2, forward delay 15, max age 20Configured hello time 2, forward delay 15, max age 20, max hops 20FastEthernet0/46 of MST00 is root forwardingPort info port id 128.46 priority 128 cost 200000 Designated root address 000f.e268.4d14 priority 32768 cost 0 Designated ist master address 000f.e268.4d14 priority 32768 cost 200000 Designated bridge address d057.4c2c.a400 priority 32768 port id 128.25 Timers: message expires in 5 sec, forward delay 0, forward transitions 1Bpdus sent 5, received 132实验拓扑三：交换机配置同上不变动观察SPANNING-TREE 状态：H3C-3600-01：<h3c-1><h3c-1>dis stp briMSTID Port Role STP State Protection0 Ethernet1/0/1 ROOT FORW ARDING NONE0 Ethernet1/0/2 DESI FORWARDING NONE1 Ethernet1/0/1 DESI FORWARDING NONE1 Ethernet1/0/2 DESI FORWARDING NONE2 Ethernet1/0/1 ROOT FORW ARDING NONE2 Ethernet1/0/2 DESI FORWARDING NONE (*) means port in aggregation group<h3c-1>dis stp ins 1-------[MSTI 1 Global Info]-------MSTI Bridge ID :4097.000f-e268-4df2MSTI RegRoot/IRPC :4097.000f-e268-4df2 / 0MSTI RootPortId :0.0Master Bridge :32768.000f-e268-4d14Cost to Master :200TC or TCN received :352----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4097.000f-e268-4df2 / 128.1Num of Vlans Mapped :2Rapid Fwd State :Rapid ForwardingPort Times :RemHops 20----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4097.000f-e268-4df2 / 128.2Num of Vlans Mapped :2Rapid Fwd State :Rapid ForwardingPort Times :RemHops 20<h3c-1>dis stp ins 2-------[MSTI 2 Global Info]-------MSTI Bridge ID :8194.000f-e268-4df2MSTI RegRoot/IRPC :4098.000f-e268-4d14 / 200MSTI RootPortId :128.1Master Bridge :32768.000f-e268-4d14Cost to Master :200TC or TCN received :227----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Role :Root PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4098.000f-e268-4d14 / 128.1Num of Vlans Mapped :2Port Times :RemHops 20----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :8194.000f-e268-4df2 / 128.2Num of Vlans Mapped :2Rapid Fwd State :Rapid ForwardingPort Times :RemHops 19H3C-3600-02：<h3c-2>dis stp briMSTID Port Role STP State Protection0 Ethernet1/0/1 DESI FORWARDING NONE0 Ethernet1/0/2 DESI FORWARDING NONE1 Ethernet1/0/1 ROOT FORWARDING NONE1 Ethernet1/0/2 DESI FORWARDING NONE2 Ethernet1/0/1 DESI FORWARDING NONE2 Ethernet1/0/2 DESI FORWARDING NONE <h3c-2>dis stp ins 1-------[MSTI 1 Global Info]-------MSTI Bridge ID :8193.000f-e268-4d14MSTI RegRoot/IRPC :4097.000f-e268-4df2 / 200MSTI RootPortId :128.1Master Bridge :32768.000f-e268-4d14Cost to Master :0TC or TCN received :115----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Role :Root PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4097.000f-e268-4df2 / 128.1Num of Vlans Mapped :2Port Times :RemHops 20----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :8193.000f-e268-4d14 / 128.2Num of Vlans Mapped :2Port Times :RemHops 19<h3c-2>dis stp ins 2-------[MSTI 2 Global Info]-------MSTI Bridge ID :4098.000f-e268-4d14MSTI RegRoot/IRPC :4098.000f-e268-4d14 / 0MSTI RootPortId :0.0Master Bridge :32768.000f-e268-4d14Cost to Master :0TC or TCN received :121----[Port1(Ethernet1/0/1)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4098.000f-e268-4d14 / 128.1Num of Vlans Mapped :2Port Times :RemHops 20----[Port2(Ethernet1/0/2)][FORW ARDING]----Port Role :Designated PortPort Priority :128Port Cost(Legacy) :Config=auto / Active=200Desg. Bridge/Port :4098.000f-e268-4d14 / 128.2Num of Vlans Mapped :2Port Times :RemHops 20CISCO 3560：Switch#sh spanning-tree mst 1 de##### MST1 vlans mapped: 110,120Bridge address d057.4c2c.a400 priority 32769 (32768 sysid 1)Root address 000f.e268.4df2 priority 4097 (4096 sysid 1)port Fa0/21 cost 200000 rem hops 19 FastEthernet0/21 of MST1 is root forwardingPort info port id 128.23 priority 128 cost 200000 Designated root address 000f.e268.4df2 priority 4097 cost 0 Designated bridge address 000f.e268.4df2 priority 4097 port id 128.2 Timers: message expires in 4 sec, forward delay 0, forward transitions 4Bpdus (MRecords) sent 35, received 2054FastEthernet0/22 of MST1 is designated forwardingPort info port id 128.24 priority 128 cost 200000 Designated root address 000f.e268.4df2 priority 4097 cost 200000 Designated bridge address d057.4c2c.a400 priority 32769 port id 128.24 Timers: message expires in 0 sec, forward delay 0, forward transitions 1Bpdus (MRecords) sent 640, received 496Switch#sh spanning-tree mst 2 de##### MST2 vlans mapped: 130,140Bridge address d057.4c2c.a400 priority 32770 (32768 sysid 2)Root address 000f.e268.4d14 priority 4098 (4096 sysid 2)port Fa0/21 cost 200200 rem hops 18 FastEthernet0/21 of MST2 is root forwardingPort info port id 128.23 priority 128 cost 200000 Designated root address 000f.e268.4d14 priority 4098 cost 200 Designated bridge address 000f.e268.4df2 priority 8194 port id 128.2 Timers: message expires in 5 sec, forward delay 0, forward transitions 3Bpdus (MRecords) sent 35, received 2058FastEthernet0/22 of MST2 is alternate blockingPort info port id 128.24 priority 128 cost 200000 Designated root address 000f.e268.4d14 priority 4098 cost 200000 Designated bridge address 0014.a897.e880 priority 32770 port id 128.45 Timers: message expires in 5 sec, forward delay 0, forward transitions 1Bpdus (MRecords) sent 657, received 509CISCO 3550：SW2#sh spanning-tree mst 1 de###### MST01 vlans mapped: 110,120Bridge address 0014.a897.e880 priority 32769 (32768 sysid 1)Root address 000f.e268.4df2 priority 4097 (4096 sysid 1)port Fa0/46 cost 200200 rem hops 18 FastEthernet0/45 of MST01 is alternate blockingPort info port id 128.45 priority 128 cost 200000 Designated root address 000f.e268.4df2 priority 4097 cost 200000 Designated bridge address d057.4c2c.a400 priority 32769 port id 128.24 Timers: message expires in 5 sec, forward delay 0, forward transitions 1Bpdus (MRecords) sent 742, received 944FastEthernet0/46 of MST01 is root forwardingPort info port id 128.46 priority 128 cost 200000 Designated root address 000f.e268.4df2 priority 4097 cost 200 Designated bridge address 000f.e268.4d14 priority 8193 port id 128.2 Timers: message expires in 5 sec, forward delay 0, forward transitions 1Bpdus (MRecords) sent 8, received 206SW2#sh spanning-tree mst 2 de###### MST02 vlans mapped: 130,140Bridge address 0014.a897.e880 priority 32770 (32768 sysid 2)Root address 000f.e268.4d14 priority 4098 (4096 sysid 2)port Fa0/46 cost 200000 rem hops 19 FastEthernet0/45 of MST02 is designated forwardingPort info port id 128.45 priority 128 cost 200000 Designated root address 000f.e268.4d14 priority 4098 cost 200000 Designated bridge address 0014.a897.e880 priority 32770 port id 128.45 Timers: message expires in 0 sec, forward delay 0, forward transitions 2Bpdus (MRecords) sent 750, received 954FastEthernet0/46 of MST02 is root forwardingPort info port id 128.46 priority 128 cost 200000 Designated root address 000f.e268.4d14 priority 4098 cost 0Designated bridge address 000f.e268.4d14 priority 4098 port id 128.2 Timers: message expires in 4 sec, forward delay 0, forward transitions 1Bpdus (MRecords) sent 8, received 208。
cisco和h3cstp对接
1、STP协议-厂商支持情况H3C交换机支持的生成树协议类型H3C交换机支持的生成树协议有三种类型，分别是STP（IEEE 802.1D）、RSTP（IEEE 802.1W）和MSTP（IEEE 802.1S），这三种类型的生成树协议均按照标准协议的规定实现，采用标准的生成树协议报文格式，大多数交换机采用固定的MAC地址00-E0-FC- 09-BC-F9作为生成树协议报文的源MAC地址，目的MAC地址为01-80-C2-00-00-00。
Cisco交换机支持的生成树协议类型Cisco交换机所支持的生成树协议类型分别有：PVST（Per VLAN Spanning Tree）、PVST+（Per VLAN Spanning Tree Plus）、Rapid-PVST+（Rapid Per VLAN Spanning Tree Plus）、MISTP（Multi Instance Spanning Tree Protocol）和MST（Multiple Spanning Tree）。
在使用IOS 12.2及之后版本的catalyst系列交换机中，支持PVST+、Rapid-PVST和MST三种类型STP协议。
同时，Cisco 所采用的STP 协议的BPDU报文格式和标准STP协议的BPDU报文格式不一样，而且发送的目的地址也改成了C友商自己的保留地址01-00-0C-CC-CC- CD。
2、STP协议-对接情况当Cisco设备使用Trunk端口与其他厂商设备的Trunk端口互联时，虽然可以做到STP的互通，以及消除环路，但是无法做到PVST协议自身的负载，原因是在其他VLAN中H3C的设备会把Cisco的BPDU报文当作普通的多播报文进行转发，而不会处理这些报文。
Cisco设备在非VLAN1中的BPDU报文不是标准的STP协议BPDU报文，而是其私有的PVST 协议报文。
当H3C交换机与Cisco交换机使用MSTP协议互通时，必须要在全局配置stp config-digest-snooping命令，同时在与Cisco设备互联的端口上也要配置该命令，才能完成与Cisco的域内MSTP协议互通。
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1、H3C交换机与CISCO交换机的MST互通
（1）由于思科对于mstp摘要计算方法特殊，导致H3C交换机和CISCO交换机在做MSTP对接时，即使它们的域配置相同，各自计算出的配置摘要也会不相同；
（2）可通过如下方法和CISCO MSTP实现域内多实例的互通：
保证H3C交换机和CISCO交换机的MSTP域配置完全相同；
在全局和任一个和CISCO交换机相连的端口上使能Configuration Digest Snooping功能：stp config-digest-snooping。
[系统视图]stp config-digest-snooping
[端口视图]stp config-digest-snooping
（3）由于CISCO的MSTP状态机实现机制与H3C的有所不同，导致CISCO设备与H3C设备相连的指定端口不能快速迁移到Fowarding状态。
为实现快速迁移，可在和CISCO设备互连的端口配置下面的命令：
[端口视图] stp no-agreement-check
[系统视图] stp interface interfacename no-agreement-check
2、H3C交换机与PVST+互通问题
（1）PVST+是基于vlan的私有协议，要与之互通必须满足一定条件才能互通配合；
（2）PVST+在端口PVID的VLAN里发送的是标准BPDU报文，但在其它VLAN内发送的是特殊的SNAP报文。
对于SNAP封装的Type字段，在以太网封装中，对Type 字段要求是值必须大于0x600，以此来区分Type和Length。
（3）正是由于PVST+报文封装格式中这个字段导致报文可能被许多设备丢弃而不做二层转发。
在组网时：
access口可以互通。
如果是trunk口，则必须保证下游discarding端口与PVST+逻辑discarding端口一致。
也就是说标准stp设备只能做下游设备，不得做根。
PVST+与mstp多实例无法互连。
由于CISCO MSTP 计算配置摘要的算法与IEEE的规定算法存在差异，导致了采用IEEE推荐算法的交换机（如H3C S系列交换机）和CISCO交换机互联时，即使交换机都具有相同的域配置，各自计算出的配置摘要也会不同，所以它们不会认为在一个域内。
因此这些交换机将工作在不同的MST域内，而不是在同一个MST域.
解决办法:
(1) 在保证相连的H3C交换机域配置和CISCO 交换机域配置完全一致的前提下，可以通过命令在每一个和CISCO 交换机相连的端口上使能CONFIGURATION DIGEST SNOOPING 功能。
对于使能了CONFIGURATION DIGEST SNOOPING 功能的端口，在接收到CISCO MSTP 报文时，直接认为报文来自域内，同时记录下报文中的配置摘要；在发送MSTP 报文时，将之前记录的配置摘要填充到发送的报文中，这就保证了CISCO 交换机接收到该报文时也认为它来自域内，这样H3C MSTP 和CISCO MSTP 的域内MSTI 就可以互通了。
(2) 如果CISCO 设备支持MSTP 标准报文，并且使用标准报文，那么CISCO 设备完全\符合IEEE MSTP 协议，其中也包括报文摘要字段，所以只要将H3C 设备配置成发送标准报文就可以完成设备的互通。