On Dell EMC switches in SmartFabric mode, Rapid Per-VLAN Spanning Tree Plus (RPVST+) is enabled globally and automatically configured. Other spanning tree protocols are not supported.
Spanning tree is not supported within OS10 for VxLAN Networks, so when virtual networks created by users using OMNI or those that are automatically created through vCenter Integration are extended on the L2 customer network uplink, spanning tree is disabled for these networks and the external switch does not receive any STP BPDUs from the fabric.
Spanning tree is automatically disabled on server-facing ports.
Spanning tree is also disabled on routed interfaces used for L3 uplinks for external network connectivity.
If L3 uplinks are created using VLAN-based networks with IP addresses, the fabric uses RPVST+ for loop prevention. Also, if user-created, VLAN-based networks are added to the L2 uplink, the fabric uses RPVST+ for loop prevention.
On L2 uplinks to external networks, spanning tree is disabled. In order to prevent network loops, a network in the fabric can only be extended on one L2 uplink to the external network.
For L3 VLAN uplinks, RPVST+ is supported.