I have 4 crs326-24g-2s+ and one crs309-1g-8s+ devices. I updated them to SWOS 2.18 a few days ago. The activity leds on each switch pulse for all connected ports at about 3 times per second, all at the same time. Not the normal random activity leds.
I have a single CRS326 running routeros 6.49.19. It is in the same stack and the led activity is random as expected.
I think I can rule out broadcast traffic, otherwise the CRS running routeros would display the same led activity.
Have checked with wireshark and I can see nothing untoward going on.
Everything is working it just doesn’t look right.
Have also disabled RSTP but no change.
This has only come about when upgrading from SWOS 2.16 to 2.18.
I don’t have experience with SWOS, but I can tell you that this behavior (“activity is a pulsed LED for all ports that have activity at the same time”) is a “common” behavior for some switch manufacturers. Probably it is a mode that the used chipset supports, I guess it could be more efficient than individual blinking of each LED.
Way in the past an activity LED would be ON during the time the port is actually transmitting and OFF otherwise, but with the introduction of 1Gbit and higher speeds the ON/OFF duty cycle for low activity would be so low that the LED would be barely visible. But overall it was a much more useful mode because one could guess how busy the network was by looking at the relative intensity of the LEDs.