Symptom
Port flapping on one of the downstream switch in vpc, we may see following messages on vpc peers:
2021 Apr 19 17:48:58 CS01 %STP-2-VPC_PEER_LINK_INCONSIST_BLOCK: vPC peer-link detected BPDU receive t
imeout blocking port-channel1 VLAN1028.
2021 Apr 19 17:48:58 CS01 %STP-2-VPC_PEER_LINK_INCONSIST_BLOCK: vPC peer-link detected BPDU receive t
imeout blocking port-channel1 VLAN1029.
-snip
2021 Apr 19 17:48:58 CS01 %STP-2-VPC_PEER_LINK_INCONSIST_BLOCK: vPC peer-link detected BPDU receive t
imeout blocking port-channel1 VLAN1035.
2021 Apr 19 17:48:58 CS01 %STP-2-VPC_PEER_LINK_INCONSIST_BLOCK: vPC peer-link detected BPDU receive t
imeout blocking port-channel1 VLAN1036.
2021 Apr 19 17:48:58 CS01 %STP-2-VPC_PEER_LINK_INCONSIST_UNBLOCK: vPC peer-link inconsistency cleared
unblocking port-channel1 VLAN1028.
2021 Apr 19 17:48:58 CS01 %STP-2-VPC_PEER_LINK_INCONSIST_UNBLOCK: vPC peer-link inconsistency cleared
unblocking port-channel1 VLAN1029.
2021 Apr 19 17:48:58 CS01 %STP-2-VPC_PEER_LINK_INCONSIST_UNBLOCK: vPC peer-link inconsistency cleared
unblocking port-channel1 VLAN1030.
