Is this normal, or is it a switch loop?

Hi @dgrooman

Could you please enable Zyxel Support and provide your organization/site name, this will aid us to look into your issue directly.

Hi @dgrooman

Upon reviewing your Nebula sites, we have identified that the broadcast storm is originating from switch CH48, port 8. Could you please share which device is connected to this port and check if there is a loop involving this port?

Regarding the log entry “STP topology changes,” it appears to be caused by frequent link up and down events on switch CH48, ports 27 and 38. Could you please share what devices are connected to these ports?

Hi @dgrooman

Regarding the log entry “STP topology changes,” this is a normal occurrence in the switch log because the RSTP feature is enabled by default on Nebula switches. When the switch detects link up/down events on a port, it logs these as STP topology changes. If you find these logs bothersome, you can choose to disable RSTP and enable Loop Guard on the specific port. You can find detailed instructions and guidance in this article:

Regarding the broadcast storm on switch CH48, port 8, first, I would like to ask if you are experiencing any network service impacts such as high latency or network hang-ups?

Our switch monitors traffic transmitted through ports. If there is no impact on your network services, it may simply indicate that the traffic on port 8 has exceeded the storm control limit set in Nebula Control Center. If you find these logs unnecessary, you can adjust the storm control threshold in the settings for switch port 8 under Nebula CC > Site-wide > Configure > Switches > Switch ports > Select and edit your switch CH48 Port 8.

If there is a noticeable impact on your network, please check for any loops in your network topology. Additionally, configuring storm control on that switch port can help mitigate such issues. For detailed instructions on configuring storm control, please refer to this article: