现状分析
某公司的总部包含4个部门，为了增加网络的可靠性，需要所在的交换机上配置MSTP，确保网络不会出现环路问题，同时实现负载均衡。
网络设计
- 搭建网络拓扑，配置VLAN，Trunk，链路聚合。
- 在4台交换机上配置MSTP，在交换机SW1创建两个实例，将vlan10，vlan20划分到实例1中，将vlan30，vlan40划分到实列2中。
- 通过配置MSTP，使实实例1和2的MSTI具有不同的根桥。SW1是实例1的根桥（优先级为4096），是实例2的次根桥（优先级为8192）；SW2是实例2的根桥（优先级为4096），是实例1的次根桥（优先级为8192）。- 对以上配置逐项进行测试，确保局域网中没有环路。
项目实施
MSTP的配置
SW1-SW4 配置STP模式为MSTP，配置MSTP域（SW1~SW4执行相同的命令）
[sw1]vlan batch 10 20 30 40 //创建VLAN
[sw1]stp mode mstp //STP的模式改为MSTP
[sw1]stp region-configuration //进入MST域视图
[sw1-mst-region]region-name pokes01 //MSTP域的名称pokes01
[sw1-mst-region]revision-level 1 //域的修订级别，默认MST域的修订级别为0
[sw1-mst-region]instance 1 vlan 10 20 //SMST实列和vlan映射关系
[sw1-mst-region]instance 2 vlan 30 40
[sw1-mst-region]active region-configuration //激活MSTP域配置
纯净版便于复制
vlan batch 10 20 30 40
stp mode mstp
stp region-configuration
region-name pokes01
revision-level 1
instance 1 vlan 10 20
instance 1 vlan 30 40
active region-configuration
链路聚合
[sw1]int Eth-Trunk 1
[sw1-Eth-Trunk1]trunkport GigabitEthernet 0/0/1 to 0/0/2
[sw1-Eth-Trunk1]port link-type trunk
[sw1-Eth-Trunk1]port trunk allow-pass vlan 10 20 30 40[sw2]int Eth-Trunk 1
[sw2-Eth-Trunk1]trunkport GigabitEthernet 0/0/1 to 0/0/2
[sw2-Eth-Trunk1]port link-type trunk
[sw2-Eth-Trunk1]port trunk allow-pass vlan 10 20 30 40
接入层和核心层的trunk配置
[sw1-GigabitEthernet0/0/3]dis th
interface GigabitEthernet0/0/3port link-type trunkport trunk allow-pass vlan 10 20[sw1-GigabitEthernet0/0/4]dis th
interface GigabitEthernet0/0/4port link-type trunkport trunk allow-pass vlan 30 40[sw2-GigabitEthernet0/0/3]dis th
#
interface GigabitEthernet0/0/3port link-type trunkport trunk allow-pass vlan 30 40[sw1-GigabitEthernet0/0/3]dis th
#
interface GigabitEthernet0/0/4port link-type trunkport trunk allow-pass vlan 10 20[sw3-GigabitEthernet0/0/1]dis th
#
interface GigabitEthernet0/0/1port link-type trunkport trunk allow-pass vlan 10 20[sw3-GigabitEthernet0/0/2]dis th
#
interface GigabitEthernet0/0/2port link-type trunkport trunk allow-pass vlan 10 20[sw4-GigabitEthernet0/0/1]dis th
#
interface GigabitEthernet0/0/1port link-type trunkport trunk allow-pass vlan 30 40[sw4-GigabitEthernet0/0/2]dis th
#
interface GigabitEthernet0/0/2port link-type trunkport trunk allow-pass vlan 30 40
接入层的vlan配置
sw3
interface GigabitEthernet0/0/12port link-type accessport default vlan 10
#
interface GigabitEthernet0/0/13port link-type accessport default vlan 20
sw4
interface GigabitEthernet0/0/14port link-type accessport default vlan 30
#
interface GigabitEthernet0/0/15port link-type accessport default vlan 40
至此已经基本配置完毕了，接下来我们需要调试SMTP的优先级
调试SMTP的优先级
[SW1]stp instance 0 priority 4096
[sw1]stp instance 1 priority 4096
[sw1]stp instance 2 priority 8192[sw2]stp instance 0 priority 8192
[sw2]stp instance 1 priority 8192
[sw2]stp instance 2 priority 4096
查看信息
[sw1]dis stp region-configuration Oper configurationFormat selector :0 //格式选择器Region name :pokes01 //配置名称Revision level :1 //修订级别Instance VLANs Mapped //实列和VLAN映射表0 1 to 9, 11 to 19, 21 to 29, 31 to 39, 41 to 40941 10, 202 30, 40[sw1]dis stp topology-change CIST topology change information //CIST拓扑变化信息Number of topology changes :42 //从MSTP初始化开始，发送拓扑变化的总计次数Time since last topology change :0 days 0h:0m:48s //距离最近一次变化时间Topology change initiator(notified) :Eth-Trunk1 //收到报文而触发的端口Topology change last received from :4c1f-cce1-3e13 //拓扑变化报文来源的桥MAC地址Number of generated topologychange traps : 21 //产生的告警次数Number of suppressed topologychange traps: 2 //抑制的告警次数MSTI 1 topology change informationNumber of topology changes :25Time since last topology change :0 days 0h:0m:48sTopology change initiator(notified) :Eth-Trunk1Topology change last received from :4c1f-cce1-3e13Number of generated topologychange traps : 21Number of suppressed topologychange traps: 2MSTI 2 topology change informationNumber of topology changes :2Time since last topology change :0 days 0h:0m:16sTopology change initiator(detected) :GigabitEthernet0/0/4Number of generated topologychange traps : 21Number of suppressed topologychange traps: 2
