Overview of RPVST+


For information on configuring basic and multiple instance spanning tree, see Multiple instance spanning tree operation.

RPVST+ is a proprietary spanning tree implementation that extends RSTP (802.1w) to run a separate spanning tree for each VLAN on the switch, and ensures that only one active, loop-free path exists between any two nodes on a given VLAN.

RPVST scalability


Maximum Allowed RPVST Enabled VLANs

Recommended Maximum Virtual Ports

Maximum Allowed Virtual Ports (x is the number of logical ports in the system)




250 + x

Where x is the sum of all physical ports and logical interface, such as Trk1 if configured.

The following shows how x is calculated using the 2920 switch as an example, you can substitute the actual values for your switch as shown in the table to do a similar calculation. In a stack of 4 with 2x2920-24 and 1 trunk interface Trk1 configured, x will be 24+24+1=49. Therefore the maximum allowed vPorts is 299.

Switch# show spanning-tree system-limits rapid-pvst

 Spanning Tree Information 

  STP Enabled              : No 
  Mode                     : MSTP 
  RPVST Enabled VLANs      : 1,4,20-23 

  Switch MAC Address                   : 40a8f0-0df69e 
  Count of RPVST Enabled GVRP VLANs    : 0 
  Count of RPVST Enabled VLANs         : 6 
  Maximum Allowed RPVST Enabled VLANs  : 64 
  Count Of Total Virtual Ports         : 51 
  Maximum Allowed Virtual Ports        : 299

                       Current         Operational     Recommended Maximum 
  Ports                Virtual Ports   Virtual Ports   Virtual Ports 
  -------------------- --------------- --------------- -------------------- 
  Member 1/1-24        31              27              250 
  Member 2/1-24        31              24              250