【思唯网络学院】生成树（STP）配置示例

rx online

如下图为某小型企业网络结构图

默认要求阻塞交换机S2与S1之间的链路以免发生环路，当核心交换机S1与S2或S3之间出现链路故障时又能从S2和S3连通到核心交换机S1.

默认要求阻塞S2的GE0/0/2端口

具体配置

[s1]stp mode stp

[s1]stp enable

[s1]stp root primary #设置为根交换机

或

[s1]stp priority ?

INTEGER<0-61440> Bridge priority, in steps of 4096 #数值越小越能称为根交换机

———————–

<s1>dis cu

sysname s1

vlan batch 10 20 200

stp mode stp

stp instance 0 root primary #设置为根交换机

interface Vlanif1

interface Vlanif10

ip address 192.168.10.254 255.255.255.0

interface Vlanif20

ip address 192.168.20.254 255.255.255.0

interface Vlanif200

ip address 192.168.200.254 255.255.255.0

interface MEth0/0/1

interface GigabitEthernet0/0/1

port link-type trunk

port trunk allow-pass vlan 2 to 4094

interface GigabitEthernet0/0/2

port link-type trunk

port trunk allow-pass vlan 2 to 4094

interface GigabitEthernet0/0/23

port link-type access

port default vlan 200

interface GigabitEthernet0/0/24

port link-type access

return

<s1>

————–

<s1>display stp

——-[CIST Global Info][Mode STP]——-

CIST Bridge :0 .4c1f-cc0c-7730 # 0表示根交换机

Config Times :Hello 2s MaxAge 20s FwDly 15s MaxHop 20

Active Times :Hello 2s MaxAge 20s FwDly 15s MaxHop 20

CIST Root/ERPC :0 .4c1f-cc0c-7730 / 0

CIST RegRoot/IRPC :0 .4c1f-cc0c-7730 / 0

CIST RootPortId :0.0

BPDU-Protection

isabled

CIST Root Type

rimary root

TC or TCN received :10

TC count per hello :0

STP Converge Mode :Normal

Time since last TC :0 days 0h:23m:15s

Number of TC :18

Last TC occurred :GigabitEthernet0/0/2

————————-

<s1>display stp brief

MSTID Port Role STP State Protection

0 GigabitEthernet0/0/1 DESI FORWARDING NONE

0 GigabitEthernet0/0/2 DESI FORWARDING NONE

0 GigabitEthernet0/0/3 DESI FORWARDING NONE

0 GigabitEthernet0/0/23 DESI FORWARDING NONE

==========================

[s3]stp mode stp

[s3]stp enable

[s3-GigabitEthernet0/0/1]stp cost 1 #设置端口开销值数值越小越能称为根端口，越大越可能成为阻塞端口

[s3-GigabitEthernet0/0/2]stp cost 20000000 #7为0

[s3]stp root secondary #设置为备份交换机

———-

<s3>dis cu

sysname s3

vlan batch 10 20

stp mode stp

stp instance 0 root secondary #备份交换机

interface Vlanif1

interface MEth0/0/1

interface Ethernet0/0/22

port link-type access

port default vlan 20

interface GigabitEthernet0/0/1

port link-type trunk

port trunk allow-pass vlan 2 to 4094

stp instance 0 cost 1

interface GigabitEthernet0/0/2

port link-type trunk

port trunk allow-pass vlan 2 to 4094

stp instance 0 cost 20000000 #7位0

return

<s3>

———————-

<s3>display stp

——-[CIST Global Info][Mode STP]——-

CIST Bridge :4096 .4c1f-cc6a-9c8e # 4096 表示备份交换机

Config Times :Hello 2s MaxAge 20s FwDly 15s MaxHop 20

Active Times :Hello 2s MaxAge 20s FwDly 15s MaxHop 20

CIST Root/ERPC :0 .4c1f-cc0c-7730 / 1

CIST RegRoot/IRPC :4096 .4c1f-cc6a-9c8e / 0

CIST RootPortId :128.23

BPDU-Protection

isabled

CIST Root Type :Secondary root

TC or TCN received :80

TC count per hello :0

STP Converge Mode :Normal

Time since last TC :0 days 0h:26m:9s

Number of TC :18

Last TC occurred :GigabitEthernet0/0/1

———————-

<s3>display stp brief

MSTID Port Role STP State Protection

0 Ethernet0/0/22 DESI FORWARDING NONE # DESI 表示指定端口

0 GigabitEthernet0/0/1 ROOT FORWARDING NONE # root 表示根端口

0 GigabitEthernet0/0/2 DESI FORWARDING NONE

============================

[s2]stp mode stp

[s2]stp enable

[s2-GigabitEthernet0/0/2]stp cost 200000000 #8位0

[s2-GigabitEthernet0/0/1]stp cost 1

—————–

[s2]dis cu

sysname s2

vlan batch 10 20

stp mode stp

interface Vlanif1

interface Ethernet0/0/22

port link-type access

port default vlan 10

interface GigabitEthernet0/0/1

port link-type trunk

port trunk allow-pass vlan 2 to 4094

stp instance 0 cost 1

interface GigabitEthernet0/0/2

port link-type trunk

port trunk allow-pass vlan 2 to 4094

stp instance 0 cost 200000000 # 8位0

return

[s2]

————–

[s2] dis stp

——-[CIST Global Info][Mode STP]——-

CIST Bridge :32768.4c1f-ccb2-e471

Config Times :Hello 2s MaxAge 20s FwDly 15s MaxHop 20

Active Times :Hello 2s MaxAge 20s FwDly 15s MaxHop 20

CIST Root/ERPC :0 .4c1f-cc0c-7730 / 1

CIST RegRoot/IRPC :32768.4c1f-ccb2-e471 / 0

CIST RootPortId :128.23

BPDU-Protection

isabled

TC or TCN received :139

TC count per hello :0

STP Converge Mode :Normal

Time since last TC :0 days 0h:34m:35s

Number of TC :16

Last TC occurred :GigabitEthernet0/0/1

—————-

[s2]dis stp br

MSTID Port Role STP State Protection

0 Ethernet0/0/22 DESI FORWARDING NONE

0 GigabitEthernet0/0/1 ROOT FORWARDING NONE

0 GigabitEthernet0/0/2 ALTE DISCARDING NONE # DISCARDING关闭表示已经阻塞

————-

现在假如核心交换机S1与S3之间出现故障，用[s3-GigabitEthernet0/0/1]shutdown 模拟。

现在来看STP状态

[s3]dis stp br

MSTID Port Role STP State Protection

0 Ethernet0/0/22 DESI FORWARDING NONE

0 GigabitEthernet0/0/2 ROOT FORWARDING NONE #已经切换为根端口

—————–

[s2]dis st br

MSTID Port Role STP State Protection

0 Ethernet0/0/22 DESI FORWARDING NONE

0 GigabitEthernet0/0/1 ROOT FORWARDING NONE

0 GigabitEthernet0/0/2 DESI FORWARDING NONE #以及从阻塞状态切换为转发状态

————–

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