Spanning Tree on SD-RED

Phil - I am not sure of the topology you are looking to put in place, but picture the RED's as a layer 2 bridge between sites. (Deployed in Standard/Unified mode)  STP can be configured on the Sophos Firewalls themselves, but not on the SD-RED's since they usually just link sites together and perform basic forwarding/routing functions depending on the deployment scenario.  Refer to the below.  If STP is a requirement, you could look at deploying a small XGS 107 or above firewall in the remote sites.

Sophos Firewall: RED (Remote Ethernet Device) technical training guide

Phil - I am not sure of the topology you are looking to put in place, but picture the RED's as a layer 2 bridge between sites. (Deployed in Standard/Unified mode)  STP can be configured on the Sophos Firewalls themselves, but not on the SD-RED's since they usually just link sites together and perform basic forwarding/routing functions depending on the deployment scenario.  Refer to the below.  If STP is a requirement, you could look at deploying a small XGS 107 or above firewall in the remote sites.

Sophos Firewall: RED (Remote Ethernet Device) technical training guide