Even though the VLT enabled topology provides a loop-free environment in the VLT domain, some non-VLT member ports can end up in a loop scenario. Rapid spanning tree protocol (RSTP) and rapid per-VLAN spanning tree+ (RPVST+) modes of spanning tree protocol in VLT are supported to provide a solution for this scenario. Depending on the network topology, the primary node of the VLT domain can be designated as the root bridge.
The RPVST+ is enabled by default in Dell SmartFabric OS10. There is no need to configure RPVST+ unless the default spanning tree mode is changed.
VLT-Peer1(config)# spanning-tree mode rapid-pvst
The RSTP is enabled by using the following command.
VLT-Peer1(config)# spanning-tree mode rstp
For Multiple Spanning Tree Protocol (MSTP) on VLT nodes, configure both VLT peer nodes in the same MST region to avoid network loops. Ensure that the VLAN-to-instance mappings, region name, and revision ID are the same on both VLT peer nodes.
VLT-Peer1(config)# spanning-tree mode mst
VLT-Peer1(config)# spanning-tree mst configuration
VLT-Peer1(conf-mst)# instance 1 vlan 2-10
VLT-Peer1(conf-mst)# revision 10
VLT-Peer1(conf-mst)# name ExampleMSTregion