28.3.3 Notes on using PVST +

(1) Coexistence with other functions

[See "24.3 Coexistence of Layer 2 Switch Function and Other Functions"

(2) About VLAN 1 (default VLAN) PVST + and Single Spanning Tree

Single Spanning Tree and VLAN 1 PVST+ cannot run at the same time. When Single Spanning Tree runs, the VLAN 1 PVST+ stops.

(3) Prohibited configuration

Configure the Switch and switches running on Single Spanning Tree within one Spanning Tree. Configurations using more than one Spanning Tree will not result in a valid topology.

The figure below shows an example of a prohibited configuration. In this example, because the switch E Single Spanning Tree is connected to more than one PVST+ Spanning Tree, the topology is not valid.

Figure 28-7: Example of prohibited configuration with Single Spanning Tree