我正在处理一个包含物理循环的相当小的第 2 层网络段。（我在下面包含了一张拓扑图）。核心交换机堆叠3850s。其他交换机为SG300系列小型企业交换机。
所有交换机之间的链路是允许 vlan 1,503,508,590 的中继
生成树似乎按预期运行，并且连接到 SW4 的 SW3 上的接口被置于阻塞状态。
我遇到的问题是核心交换机会定期记录到 SW1 和 SW2 的链路之间的 MAC Flap 事件。
%SW_MATM-4-MACFLAP_NOTIF: Host 00eb.d5f2.0b9a in vlan 1 is flapping between port Po1 and port Po2
有问题的 MAC 地址似乎是 Cisco MAC（可能是分配给端口组的 MAC 地址？）但是我无法在物理上找到它所属的交换机。当我移除环路时，核心说 MAC 可通过 Po2（到 SW2 的链接）获得，但是 SW2 说 MAC 可通过 Po1（到核心的上行链路）获得。
我的问题是：
如何确定这个 MAC 地址实际上也属于哪个交换机？
什么可能导致端口之间的这种周期性波动？
这是所有交换机到交换机链路的当前配置以及每个交换机的完整 MAC 地址表。
核心交换机接口配置：
interface GigabitEthernet1/1/1
description Po1 Member1
switchport trunk allowed vlan 1,503,508,590
switchport mode trunk
switchport nonegotiate
channel-group 1 mode active
end
!
interface GigabitEthernet1/1/2
description Po2 Member1
switchport trunk allowed vlan 1,503,508,590
switchport mode trunk
switchport nonegotiate
channel-group 2 mode active
end
!
interface GigabitEthernet2/1/1
description Po1 Member2
switchport trunk allowed vlan 1,503,508,590
switchport mode trunk
switchport nonegotiate
channel-group 1 mode active
end
!
interface GigabitEthernet2/1/2
description Po2 Member2
switchport trunk allowed vlan 1,503,508,590
switchport mode trunk
switchport nonegotiate
channel-group 2 mode active
end
!
interface Port-channel1
description SW1 Uplink
switchport trunk allowed vlan 1,503,508,590
switchport mode trunk
switchport nonegotiate
end
!
interface Port-channel2
description SW2 Uplink
switchport trunk allowed vlan 1,503,508,590
switchport mode trunk
switchport nonegotiate
end
SW1接口配置：
interface gigabitethernet51
channel-group 1 mode auto
!
interface gigabitethernet52
channel-group 1 mode auto
!
interface Port-channel1
description "Core Uplink"
switchport trunk allowed vlan add 503,508,590
!
interface gigabitethernet50
description "Uplink to SW3"
switchport trunk allowed vlan add 503,508,590
!
SW2接口配置：
interface gigabitethernet51
channel-group 1 mode auto
!
interface gigabitethernet52
channel-group 1 mode auto
!
interface Port-channel1
description "Core Uplink"
switchport trunk allowed vlan add 503,508,590
!
interface gigabitethernet50
description "Uplink to SW4"
switchport trunk allowed vlan add 503,508,590
!
SW3接口配置：
interface gigabitethernet49
description "UPLNK to SW4"
switchport trunk allowed vlan add 503,508,590
!
interface gigabitethernet50
description "UPLINK TO SW1"
switchport trunk allowed vlan add 503,508,590
!
SW4接口配置：
interface gigabitethernet49
description "UPLNK to SW3"
switchport trunk allowed vlan add 503,508,590
!
interface gigabitethernet50
description "UPLINK TO SW2"
switchport trunk allowed vlan add 503,508,590
!
核心交换机 MAC 表00eb.d5f2.0b9a：
Vlan Mac Address Type Ports
---- ----------- -------- -----
1 00eb.d5f2.0b9a DYNAMIC Po1
SW1 MAC 表00:eb:d5:f2:0b:9a：
Vlan Mac Address Port Type
------------ --------------------- ---------- ----------
1 00:eb:d5:f2:0b:9a gi50 dynamic
SW2 MAC 表00:eb:d5:f2:0b:9a：
Vlan Mac Address Port Type
------------ --------------------- ---------- ----------
1 00:eb:d5:f2:0b:9a Po1 dynamic
503 00:eb:d5:f2:0b:9a Po1 dynamic
508 00:eb:d5:f2:0b:9a Po1 dynamic
590 00:eb:d5:f2:0b:9a Po1 dynamic
SW3 MAC 表用于00:eb:d5:f2:0b:9a：
Vlan Mac Address Port Type
------------ --------------------- ---------- ----------
SW4 MAC 表用于00:eb:d5:f2:0b:9a：
Vlan Mac Address Port Type
------------ --------------------- ---------- ----------
1 00:eb:d5:f2:0b:9a gi50 dynamic
503 00:eb:d5:f2:0b:9a gi50 dynamic
508 00:eb:d5:f2:0b:9a gi50 dynamic
590 00:eb:d5:f2:0b:9a gi50 dynamic
显示“核心开关”的 cdp nei：
Device ID Local Intrfce Holdtme Capability Platform Port ID
SW2
Gig 2/1/2 146 S I SG300-52 gi52
SW2
Gig 1/1/2 146 S I SG300-52 gi51
SW1
Gig 2/1/1 123 S I SG300-52 gi52
SW1
Gig 1/1/1 123 S I SG300-52 gi51
