Administrator Guide

Layer 2 Switching Commands 772
• rapid-pvst — Spanning-tree operates in RSTP-PV mode.
Default Configuration
Rapid Spanning Tree Protocol (RSTP) is enabled.
Command Mode
Global Configuration mode
User Guidelines
In RSTP mode, the switch uses STP when the neighbor switch is using STP.
In MSTP mode, the switch uses RSTP when the neighbor switch is using
RSTP and uses STP when the neighbor switch is using STP.
Only one of STP, RSTP, MSTP (RSTP), STP-PV or RSTP-PV can be enabled
on a switch. This command stops all spanning-tree instances in the current
mode and enables spanning-tree per VLAN in the new mode. By default,
RSTP is enabled.
If configuring the switch to MSTP mode, be sure to configure the MST
region name. For multiple switches to become members of the same region,
the configuration name, the configuration revision and mapping of VLANs to
MSTIs must be identical.
In the STP-PV or RSTP-PV modes, BPDUs contain per-VLAN information
instead of the common spanning-tree information (MST/RSTP).
RSTP-PV maintains independent spanning tree information about each
configured VLAN. RSTP-PV uses IEEE 802.1Q trunking and allows a trunked
VLAN to maintain blocked or forwarding state per port on a per VLAN basis.
This allows a trunk port to be forwarding for some VLANs and blocked on
other VLANs.
RSTP-PV extends the IEEE 802.1w standard. It supports faster convergence
than IEEE 802.1D. RSTP-PV is compatible with IEEE 802.1D spanning tree.
RSTP-PV sends BPDUs on all ports instead of only the root bridge sending
BPDUs and supports the discarding, learning, and forwarding states.
When the mode is changed to rapid-pvst, version 0 STP BPDUs are no longer
transmitted and version 2 RSTP-PV BPDUs that carry per-VLAN information
are transmitted on the VLANs enabled for spanning-tree. If a version 0 BPDU
is seen, RSTP-PV reverts to sending version 0 BPDUs.
2CSNXXX_SWUM204.book Page 772 Monday, January 25, 2016 1:25 PM