Replaced two DLink 1210ME to Mikrotik CRS-125.
So speed on Erh-port can’t up to 1Gb, but DLink worked well without errors.
One DLink and one Mikrotik give 100mbit too.
Two Dlinks 1Gb normal speed.
Line is about 100m cable cat 5e.
Is this normal situation?
Try cat6 cable instead, should solve your issue. You’re at the edge of the spec and many cables do not meet their spec.
When errors are detected on the line the speed is dropped.
And optics even better.
It’s a shame that the Dlink is working well but mikrotik can’t.