I have wired behavior with SPF+port12 on my CCR .. from time to time is flapping is reporting DOWN then UP.
On the other side on my Synology nas is not behaving like this.
Is not the DAC cable as i have chenaged the DAC cable .
I have moved the connection from SPF+Port12 to SFP+Port9 and is fine ..
There is any way to put the port on debug mode to identify why the port is flapping.
Please see attachement.