网络工程 - 长距离链路上的 STP 环路问题 - 吾爱随笔录

我通过我们的 ISP 网络在西海岸到东成本数据中心之间建立了长距离连接，如下图所示（BSN=Boston，PHX=Phoenix）

现在，当 ISP-A 或 ISP-B 在此期间进行任何维护时，PHX-SW1 交换机将接口置于 LOOP*（ofc，因为在 ISP 关闭期间缺少 BPDU，但好奇为什么它认为它的环路并试图保护链路？有什么吗？我应该做长距离 STP 调谐吗？）

PHX-SW1-配置：

interface Ethernet1/1
  switchport mode trunk
  switchport trunk allowed vlan 4

这是 ISP-A 宕机时的情况

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Eth1/1           Root BKN*4         128.1    P2p *LOOP_Inc
Eth1/2           Root FWD 4         128.2    P2p 
Eth1/3           Altn BLK 4         128.3    P2p 
Eth1/4           Desg FWD 4         128.4    P2p 

PHX-SW1# 2021 Aug 31 21:02:10 PHX-SW1 %$ VDC-1 %$ %STP-2-LOOPGUARD_BLOCK: Loop guard blocking port Ethernet1/1 on VLAN0004.

当 ISP-A 启动时，它会解除对接口的阻止并且一切恢复正常。

更新 - 1

BSN-SW1并且BSN-SW2在vPC

BSN-SW1

BSN-SW1# show spanning-tree vlan 4

VLAN0004
  Spanning tree enabled protocol rstp
  Root ID    Priority    4100
             Address     0023.04ee.be01
             This bridge is the root
             Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    4100   (priority 4096 sys-id-ext 4)
             Address     0023.04ee.be01
             Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po999            Root FWD 4         128.5094 (vPC peer-link) Network P2p 
Eth1/1           Desg FWD 4         128.1    P2p 
Eth1/2           Desg FWD 4         128.2    P2p

BSN-SW2

BSN-SW2# show spanning-tree vlan 4

VLAN0004
  Spanning tree enabled protocol rstp
  Root ID    Priority    4100
             Address     0023.04ee.be01
             This bridge is the root
             Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    4100   (priority 4096 sys-id-ext 4)
             Address     0023.04ee.be01
             Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po999            Desg FWD 4         128.5094 (vPC peer-link) Network P2p 
Eth1/1           Desg FWD 4         128.1    P2p 
Eth1/2           Desg FWD 4         128.2    P2p

PHX-SW1

PHX-SW1# show spanning-tree vlan 4

VLAN0004
  Spanning tree enabled protocol rstp
  Root ID    Priority    4100
             Address     0023.04ee.be01
             Cost        4
             Port        1 (Ethernet1/1)
             Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32772  (priority 32768 sys-id-ext 4)
             Address     5254.0018.7292
             Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Eth1/1           Root FWD 4         128.1    P2p 
Eth1/2           Altn BLK 4         128.2    P2p 
Eth1/3           Altn BLK 4         128.3    P2p 
Eth1/4           Desg FWD 4         128.4    P2p

PHX-SW2

PHX-SW2# show spanning-tree vlan 4

VLAN0004
  Spanning tree enabled protocol rstp
  Root ID    Priority    4100
             Address     0023.04ee.be01
             Cost        4
             Port        1 (Ethernet1/1)
             Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32772  (priority 32768 sys-id-ext 4)
             Address     5254.0008.b08b
             Hello Time  2  sec  Max Age 20 sec  Forward Delay 15 sec

Interface        Role Sts Cost      Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Eth1/1           Root FWD 4         128.1    P2p 
Eth1/2           Desg FWD 4         128.2    P2p 
Eth1/3           Desg FWD 4         128.3    P2p