8.8 STP

1.配置STP

[sw1]stp enable
[sw1]stp mode stp
[sw2]stp enable          
[sw2]stp mode stp
[SW3]stp enable 
[SW3]stp mode stp 

2.查看STP状态信息

[sw1]display stp
-------[CIST Global Info][Mode STP]-------
CIST Bridge         :32768.4c1f-ccfb-35ef
Config Times        :Hello 2s MaxAge 20s FwDly 15s MaxHop 20
Active Times        :Hello 2s MaxAge 20s FwDly 15s MaxHop 20
CIST Root/ERPC      :32768.4c1f-cca7-7b31 / 20000
CIST RegRoot/IRPC   :32768.4c1f-ccfb-35ef / 0
CIST RootPortId     :128.2
BPDU-Protection     :Disabled
TC or TCN received  :41
TC count per hello  :0
STP Converge Mode   :Normal 
Time since last TC  :0 days 0h:0m:52s
Number of TC        :6
Last TC occurred    :GigabitEthernet0/0/2

[SW3]display stp brief 
 MSTID  Port                        Role  STP State     Protection
   0    GigabitEthernet0/0/2        DESI  FORWARDING      NONE
   0    GigabitEthernet0/0/3        DESI  FORWARDING      NONE

3.配置SW1为主根，SW2为备份根

[sw1]stp priority 4096
[sw2]stp priority 8192