Tx power low alarm was output during err-disable status

[AZUMARY]

Hello,

We were connecting two Catalyst with pagp.

then It seems that HW was some broken in one of the switches.

I checked the logs on the undamaged Switch, but I do not know if this is the expected behavior.

%PM-4-ERR_DISABLE: pagp-flap error detected on Te2/7, putting Te2/7 in err-disable state

%EC-5-UNBUNDLE: Interface Te2/7 left the port-channel Po1

%LINK-3-UPDOWN: Interface TenGigabitEthernet2/7, changed state to down

%PM-4-ERR_DISABLE: pagp-flap error detected on Te2/8, putting Te2/8 in err-disable state

%EC-5-UNBUNDLE: Interface Te2/8 left the port-channel Po1

%LINK-3-UPDOWN: Interface TenGigabitEthernet2/8, changed state to down

%SFF8472-5-THRESHOLD_VIOLATION: Te2/7: Tx power low alarm; Operating value: -40.0 dBm, Threshold value: -11.3 dBm.

%SFF8472-5-THRESHOLD_VIOLATION: Te2/8: Tx power low alarm; Operating value: -40.0 dBm, Threshold value: -11.3 dBm.

The Tx power low message was output several times until port shut down manually.

Is it expected to output the TX / RX message when the interface status of "down/down(err-disable)"?

[omz]

%SFF8472-5-THRESHOLD_VIOLATION - 

The specified port is not connected, or it is connected to a damaged fiber optic cable. If the port is not connected, shut down the port. 

Operating value: -40.0 dBm, Threshold value: -11.3 dBm

Could be a bug. Do you have SFP in inactive uplink port?

Could be a faulty fiber or transceiver. I think, -40.0 dBm would indicate no light.

https://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/69980-errdisable-recovery.html