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.
|
Platform |
Maximum Allowed RPVST Enabled VLANs |
Recommended Maximum Virtual Ports |
Maximum Allowed Virtual Ports (x is the number of logical ports in the system) |
|---|---|---|---|
|
2530 |
32 |
250 |
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