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STP Dispute 保护触发后立刻退出

孙姝悦
2026-09-14 发表

告警信息

%Sep 12 22:45:45:128 2026 CTY-YZ-JS-YZ-MTDD-01D04F403-J01-12-12U05-H3C-S12508-DSW STP/4/STP_DISPUTE: Instance 0's port Bridge-Aggregation11 received an inferior BPDU from a designated port which is in forwarding or learning state. The designated bridge ID contained in the BPDU is 32768.6c87-208d-5ecc, and the designated port ID contained in the BPDU is 128.2191.

%Sep 12 22:45:45:129 2026 CTY-YZ-JS-YZ-MTDD-01D04F403-J01-12-12U05-H3C-S12508-DSW STP/4/STP_DISPUTE: Instance 0's port Bridge-Aggregation13 received an inferior BPDU from a designated port which is in forwarding or learning state. The designated bridge ID contained in the BPDU is 32768.6c87-208d-4e78, and the designated port ID contained in the BPDU is 128.2191.

%Sep 12 22:45:45:129 2026 CTY-YZ-JS-YZ-MTDD-01D04F403-J01-12-12U05-H3C-S12508-DSW STP/4/STP_DISPUTE: Instance 0's port Bridge-Aggregation12 received an inferior BPDU from a designated port which is in forwarding or learning state. The designated bridge ID contained in the BPDU is 32768.6c87-208d-623c, and the designated port ID contained in the BPDU is 128.2186.

问题描述

四个不太的聚合口同时收到了低优先级BPDU触发STP dispute阻塞接口，之后立马退出STP dipute保护。

过程分析

1、查看STP历史记录，确认根桥变化轨迹。故障期间根桥经历了多次切换：原根桥为Bagg101，随后依次变化为Bagg106、Bagg101，最终稳定在Bagg52，表明网络中有新设备接入或STP优先级变更，触发了全网拓扑重新计算。
 
2、分析BPDU报文交互过程，定位Dispute触发原因。收敛过程中各设备计算存在时间差，对端设备率先完成局部计算，向本端发送携带新根桥信息的BPDU。本端尚未完成收敛，仍认为原根桥有效，收到对端BPDU后发现其根桥优先级低于本端计算结果，满足Dispute触发条件，导致Bagg11、Bagg12、Bagg13和Bagg106接口被短暂阻塞。
 
3、确认Dispute保护持续时间及恢复过程。Dispute触发后约100ms，STP拓扑收敛完成，全网根桥信息达成一致，不再满足Dispute触发条件，保护状态自动解除，端口恢复转发，业务自动恢复。

 

解决方法

1、在网络核心设备上配置 stp primary 或 stp priority 0，将根桥固定为核心设备，确保其STP优先级始终最优，避免因新设备接入或优先级变更导致根桥漂移。
  1. 2、在非根桥设备上启用 stp root-protection 根保护功能，防止非法设备抢占根桥位置，从机制上杜绝因根桥变化引发的Dispute保护误触发。