. 1 STP (Spanning Tree Protocol).

. 1 STP
STP . STP , stp enable , STP.
# S1 STP. stp {mstp | rstp | stp}, MSTP, RSTP STP. MSTP.
<Quidway> system-view [Quidway] sysname S1 [S1] stp mode stp
# S2 STP.
<Quidway> system-view [Quidway] sysname S2 [S2] stp mode stp
# S3 STP.
<Quidway> system-view [Quidway] sysname S3 [S3] stp mode stp
# S4 STP.
<Quidway> system-view [Quidway] sysname S4 [S4] stp mode stp
STP , . . 1 : S1 S2 , , S3 S4, . S1, , S1 . stp priority priority
; 0 61440 4096. -32 768. , , . stp root primary
S1 . 0. stp priority priority
.
[S1] stp root primary
S2 , S2 S1 . stp root secondary 4096 stp priority priority.
[S2] stp root secondary
STP . SPT, display stp [interface interface-type
interface-number] [brief]
S1 display stp brief
STP.

, , S1 , GE0 / 0/2 GE0 / 0/1 S1 normal forwarding.
- STP S4.

GE0/0/2 S4 normal forwarding. GE0/0/1 .