We use the RUTX09 devices in our panels using version 07.07.3.
We are now upgrading the firmware on the routers to the latest stable release (07.15.4 at the time of testing), and we have noticed the routers have started to send BPDUs when upgrading or booting up. This seems to occur when the device is initialising.
This did not happen on the older firmware (07.07.3) but since upgrading, connected switches are going into err-disable as BPDUs are being detected.
How can this be disabled?
Within the RUTOS configuration, the “lan“ interface has bridge mode enabled, but STP disabled. Our DMZ interface does not have bridge mode enable, which therefore means STP is still disabled, but BPDUs are detected on boot. When the router is in normal operation, no BPDUs are sent from these interfaces.
Is there a firmware bug for the hardware interfaces that creates BPDUs before RUTOS initialises or is there a fix to prevent this?
I have also tested 07.16.3 and the same issue occurs.
Thank you for reaching out and providing detailed information about the BPDU behavior. Your request is currently under review, and once the evaluation is complete, I will provide you with further updates, findings, or suggestions.
In the meantime, could you please confirm which interfaces are currently bridged with the LAN interface? I also assume the issue is noticeable when running the latest firmware version, 7.17.3, as well?
Additionally, would you be able to provide screenshots of the configuration sections where changes were made? Thank you.
The issue observed is with the “dmz“ interface. Our topology is as follows.
RUTX09 --LAN-- TSW212 - No issues observed. Admin Edge has been left disabled.
–DMZ(lan2)–3rd party Cisco switch with bpduguard enabled.
–WAN-- Cisco switch - No issues observed.
List of my LAN interfaces. I have also created my DMZ interface under the WAN section and the same issue has been seen.
I have tried to turn off bridge interfaces and force link on both lan and dmz interface and alternate the configuration to see how to prevent BPDUs. But the configuration above is used on RUTX09 routers running 07.07.3 and there are no BPDUs when the router initialises.
Here is the configuration of the port based vlan section.
I have just double checked the STP packet again in the Wireshark screenshot and the 20:97:27:24:4e:0f MAC address corresponds to my TSW212 switch connected to the LAN interface.
In this case, to understand and troubleshoot this issue effectively, we’ll need to continue this process privately, because sensitive/publicly unshareable information, such as the troubleshoot file, public IP addresses, serial numbers, etc., needs to be collected.
You should find a support request form in the inbox of the email address you used for your forum registration. Kindly fill out the form, and please reference Ticket ID: 15442 when submitting it. Once the form is completed, we’ll contact you directly via email to investigate the issue in detail and help work towards a solution.
