@NadiaK, yep, you are completely correct about the MX. Although the MX doesn’t generate its own BPDUs, it does forward BPDUs that it receives out other ports. You’re limited to how you can influence the traffic flow to just modifying the root bridge priority on the switches. ... View more

Note that unlike Cisco Enterprise, you don't have to buy a Cisco Meraki licence for a warm spare.   So just buy a pair of the next size device up if needed. ... View more

Thank you Claes_Karlsson. It was firmware issue. After update everything works! ... View more