一、 组网需求
1. 网络中所有设备都属于同一个MST域。SW1和SW2为汇聚层设备，SW3和SW4为接入层设备。
2. 通过配置MSTP，使不同VLAN的报文按照不同的MSTI转发：
VLAN10的报文沿MSTI1转发，VLAN30沿MSTI3转发，VLAN40沿MSTI4转发，VLAN20沿MSTI0转发。
3. 由于VLAN10和VLAN30在汇聚层设备终结、VLAN40在接入层设备终结，因此配置MSTI1和MSTI3的根桥别为SW1和SW2，MSTI4的根桥为SW3
二、 组网图
三、 配置注意事项
1. 各设备的VLAN必须存在
2. 设备在物理上有链路连通
3. MST域：域名、修订级别、VLAN映射表必须一致
4. 新配置的MST域参数并不会马上生效，而是在使用active region-configuration命令激活，或使用命令stp enable使能生成树协议后才会生效
四、 配置步骤
4.1.设备VLAN配置
1. SW1转发VLAN10、20、30流量
2. SW2转发VLAN10、20、30流量
3. SW3转发VLAN10、20、40流量
4. SW4转发VLAN20、30、40流量
4.2.各上联口配置trunk口，并放行对应流量
4.3.配置域名、修订级别、VLAN映射关系
stp region-configuration
region-name test
instance 1 vlan 10
instance 3 vlan 30
instance 4 vlan 40
active region-configuration
revision-level 0
4.4.active region-configuration命令激活
五、 校验配置效果
[SW1]dis stp brief
0 Ethernet0/0/1 ROOT FORWARDING NONE
0 Ethernet0/0/2 DESI FORWARDING NONE
0 Ethernet0/0/3 ALTE DISCARDING NONE
1 Ethernet0/0/1 DESI FORWARDING NONE
1 Ethernet0/0/3 DESI FORWARDING NONE
3 Ethernet0/0/1 ROOT FORWARDING NONE
3 Ethernet0/0/2 DESI FORWARDING NONE
<SW2>dis stp brief
0 Ethernet0/0/1 DESI FORWARDING NONE
0 Ethernet0/0/2 DESI FORWARDING NONE
0 Ethernet0/0/3 DESI FORWARDING NONE
1 Ethernet0/0/1 ROOT FORWARDING NONE
1 Ethernet0/0/2 ALTE DISCARDING NONE
3 Ethernet0/0/1 DESI FORWARDING NONE
3 Ethernet0/0/3 DESI FORWARDING NONE
<SW3>dis stp brief
0 Ethernet0/0/1 DESI FORWARDING NONE
0 Ethernet0/0/2 ROOT FORWARDING NONE
0 Ethernet0/0/3 DESI FORWARDING NONE
1 Ethernet0/0/2 DESI FORWARDING NONE
1 Ethernet0/0/3 ROOT FORWARDING NONE
4 Ethernet0/0/1 DESI FORWARDING NONE
<SW4>dis stp brief
0 Ethernet0/0/1 ALTE DISCARDING NONE
0 Ethernet0/0/2 ALTE DISCARDING NONE
0 Ethernet0/0/3 ROOT FORWARDING NONE
3 Ethernet0/0/2 ALTE DISCARDING NONE
3 Ethernet0/0/3 ROOT FORWARDING NONE
4 Ethernet0/0/1 ROOT FORWARDING NONE
六、debugging stp event
Oct 19 2012 20:18:24.230.4-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port3 enters PIM%SUPERIOR_DESIGNATED state.
Oct 19 2012 20:18:24.230.5-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port3 enters PIM%SET Proposed(1) state.
Oct 19 2012 20:18:24.230.6-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port3 enters PIM%CLEAR Agree state.
Oct 19 2012 20:18:24.230.7-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port3 enters PIM%SET Agreed(1) state.
Oct 19 2012 20:18:24.230.8-08:00 SW4 MSTP/7/PROLE:MSTP process 0 Instance 0's Port1 is selected as DESIGNATED(3) role.
Oct 19 2012 20:18:24.230.9-08:00 SW4 MSTP/7/PROLE:MSTP process 0 Instance 0's Port2 is selected as ALTERNATE role.
Oct 19 2012 20:18:24.230.10-08:00 SW4 MSTP/7/PROLE:MSTP process 0 Instance 0's Port3 is selected as ROOT role.
Oct 19 2012 20:18:24.230.11-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PIM%UPDTINFO state.
Oct 19 2012 20:18:24.230.12-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PIM%CLEAR Agreed state.
Oct 19 2012 20:18:24.230.13-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PIM%CLEAR Synced(1) state.
Oct 19 2012 20:18:24.230.14-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PRT_RDM%ACTIVE_PORT state.
Oct 19 2012 20:18:24.230.15-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PRT_RDM%PROPOSING state.
Oct 19 2012 20:18:24.230.16-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PRT_RDM%ACTIVE_PORT state.
Oct 19 2012 20:18:24.230.17-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PRT_RDM%SYNCED state.
Oct 19 2012 20:18:24.230.18-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port2 enters PRT_RDM%AllSynced state.
Oct 19 2012 20:18:24.230.19-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port3 enters PRT_RDM%AllSynced state.
Oct 19 2012 20:18:24.230.20-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PRT_RDM%ACTIVE_PORT state.
Oct 19 2012 20:18:24.230.21-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PRT_RDM%AGREES state.
Oct 19 2012 20:18:24.230.22-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PRT_RDM%ACTIVE_PORT state.
Oct 19 2012 20:18:24.230.23-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port1 enters PRT_RDM%ACTIVE_PORT state.
Oct 19 2012 20:18:24.230.24-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port2 enters PRT_DAB%BLOCK_PORT state.
Oct 19 2012 20:18:24.230.25-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port2 enters TCM%ACTIVE state.
Oct 19 2012 20:18:24.230.26-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port2 enters TCM%INIT state.
Oct 19 2012 20:18:24.230.27-08:00 SW4 MSTP/7/FLSH:MSTP process 0 Instance 0's port2's dyna-Address is cleared
Oct 19 2012 20:18:24.230.28-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port2 enters TCM%INACTIVE state.
Oct 19 2012 20:18:24.230.29-08:00 SW4 MSTP/7/MEXS:MSTP process 0 Instance 0's port2 enters PST%DISCARDING state.
