The HDMI ports used for stacking do not participate in STP. When the switches are stacked they are managed as one unit. I wanted to clarify, when you say you cannot enable STP, does this mean you do not want STP to be enabled? Or that when you try to enable STP it gives an error/will not enable? You mentioned that ports 1 and 2 remain in a forwarding state, is this not the desired status? What status are you expecting and why? Thanks.
Helo ,   I have 2 switches in stack mode with HDMI. I use these two switches in the access layer.To connect to the distribution layer, connect the unit to a switch from one distribution layer and Unit 2 to another switch different from the distribution layer.Configure the ports as trunk, but I can not enable STP.Everything is configured with the same VLAN, and the connection works. But both ports (unit 1 and unit 2) remain forwarding.I have no other stack PowerConnect switches and operating properly.The HDMI connection is within the spanning tree? or is it just for internal use both switches??thanksregards
PowerConnect 5548 Stack and STP