PVST/PVST+ compatibility

The FastIron family of switches support Cisco's Per VLAN Spanning Tree plus (PVST+), by allowing the device to run multiple spanning trees while also interoperating with IEEE 802.1Q devices1.

Note: RUCKUS ports automatically detect PVST+ BPDUs and enable support for the BPDUs once detected. You do not need to perform any configuration steps to enable PVST+ support.

Support for Cisco's Per VLAN Spanning Tree plus (PVST+), allows a RUCKUS device to run multiple spanning trees while also interoperating with IEEE 802.1Q devices. RUCKUS ports automatically detect PVST+ BPDUs and enable support for the BPDUs once detected. The enhancement allows a port that is in PVST+ compatibility mode due to auto-detection to revert to the default multiple spanning trees mode when one of the following events occurs:

  • The link is disconnected or broken
  • The link is administratively disabled
  • The link is disabled by interaction with the link-keepalive protocol

This enhancement allows a port that was originally interoperating with PVST+ to revert to multiple spanning trees when connected to a RUCKUS device.

1 Cisco user documentation for PVST/PVST+ refers to the IEEE 802.1Q spanning tree as the Common Spanning Tree (CST).