STP BPDU sender conflict

[Kau1]

I have a couple of Meraki Switches in my topology (MS-130s) both of them. 

Current version: MS 17.2.1

The SW1 connect to SW2 via port 1. I have configured SW01 to be priority 4096.

SW01 (priority 4096) via port 1.

However, when we are trying to use a Peplink SD_WAN device to connect to port 17 on SW01, keep getting 

and the below comes up on the event logs

And the port 17 goes orange

Can you please advise if there is anything that could be causing this?

[RaphaelL]

SW01 is the root but it is receiving BPDU on a Root port that's why there is an alert.

Either "Peplink SD_WAN" on Port 17 is not receiving the BPDUs or "Peplink SD_WAN" thinks it is also the root. 

[Kau1]

Thanks for the response RaphaeIL.. should I need to make any changes on the Peplink then as it should be acting as a Router essentially?

[DarrenOC]

Hi @Kau1 - is sw01 your core switch? Are your L3 SVI’s configured on this device?  If so, lower the priority down to ‘0’ and also set the switchport 17 to Loopguard that connects your SD-WAN device.

[Kau1]

Thanks DarrenOC.. yes SW01 is the main switch but only a L2 device. OK thanks, will try the loopguard setting.

[PhilipDAth]

I don't know the answer, but Google found where the Peplink spanning tee configuration is.  Maybe take a look there.

https://forum.peplink.com/t/sd-switch-spanning-tree-default-priority/19516

You want to use Multiple Spanning Tree (MST) or any protocol that utilises untagged spanning tree packets. You could also try making the ports towards each other trunk ports (maybe that might help the Peplink with the STP packets).

Does the Peplink have a single link to the MS, or does it also connect to other switches?

[bperezgo]

Hi @Kau1, I recommend opening a case with Support. 

A packet capture on port 17 and the LAN would should show what STP bridge IDs are being received to determine whether the Peplink device is doing something.