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Per-VLAN Rapid Spanning Tree

Updated: June 15, 2026

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Introduces Per-VLAN Rapid Spanning Tree concepts and explains PVRST behavior and characteristics for optimizing per-VLAN network convergence and redundancy.

A Per-VLAN rapid span tree (PVRST) is a spanning tree protocol implementation that

  • runs a separate instance of the rapid spanning tree protocol (IEEE 802.1w) for each configured VLAN

  • assigns a single root switch to each VLAN instance, and

  • requires the feature to be configured on all VLANs for a particular port.

A single instance of spanning tree protocol (STP) operates on each configured VLAN unless manually disabled. Each Rapid PVST+ instance for a VLAN has its own root switch. When Rapid PVST+ is enabled, the feature must be configured for all VLANs present on a specific port.

Feature History Table

Feature Name

Release Information

Feature Description

Per-VLAN Rapid Spanning Tree

Release 24.4.1

Introduced in this release on: Fixed Systems (8700) (select variants only*)

*The PVRST functionality is now extended to the Cisco 8712-MOD-M routers.

Per-VLAN Rapid Spanning Tree

Release 24.3.1

Introduced in this release on: Fixed Systems (8200 [ASIC: Q200, P100], 8700 [ASIC: P100]) (select variants only*); Modular Systems (8800 [LC ASIC: Q100, Q200, P100]) (select variants only*)

*The PVRST functionality is now extended to:

  • 8212-48FH-M

  • 8711-32FH-M

  • 88-LC1-52Y8H-EM

  • 88-LC1-12TH24FH-E

Per-VLAN Rapid Spanning Tree

Release 24.2.11

Introduced in this release on: Modular Systems (8800 [LC ASIC: P100]) (select variants only*)

Per-VLAN Rapid Spanning Tree (PVRST) allows faster convergence of the spanning tree protocol by running a separate instance of STP on each configured VLAN. By configuring PVRST on all VLANs for a specific port, you can take advantage of its rapid convergence and improve network performance and resiliency.

*The PVRST functionality is now extended to routers with the 88-LC1-36EH line cards.

Characteristics of PVRST operation

  • PVRST uses point-to-point wiring to provide rapid spanning tree convergence, achieving reconfiguration times of less than 1 second—compared to 50 seconds with default IEEE 802.1D STP.

  • PVRST supports a single STP instance for each VLAN. PVRST supports up to 64 VLANs and 512 EFP instances per router.

  • Designated or root ports send a Bridge Protocol Data Unit (BPDU) every two seconds by default. If three consecutive BPDUs are missed or the maximum age timer expires, the port immediately flushes all protocol information, facilitating rapid failure detection.

  • PVRST transitions ports to the forwarding state rapidly only on edge ports and point-to-point links. Link types are automatically derived from the duplex mode: full-duplex implies point-to-point, half-duplex implies shared.

  • Forward Delay and Max Age timers are configured globally, not per VLAN. The Hello timer can be set per port, but not per VLAN; this per-port setting applies to all VLANs on the port.

  • The cost of a spanning tree bundle port is fixed at 10,000, regardless of the number or speed of bundle members, operational status, or changes in bundle membership.

  • BPDU guard, when enabled on an interface, error-disables both the physical port and any associated Layer-2 or Layer-3 sub-interfaces upon receiving a BPDU.

  • PVRST protection is available only for Ethernet Flow-points (EFPs) that are untagged or have a single VLAN tag.

  • If any EFP in a bridge domain is protected by PVRST, all EFPs within that domain must belong to the same VLAN. If any EFP on a port is protected by PVRST, all EFPs on that port must be protected.