Blade ICE RACKSWITCH G8124-E - Manual (Page 126)

BLADEOS 6.5.2 Application Guide
126 Chapter 8: Spanning Tree Protocols BMD00220, October 2010
Per-VLAN Rapid Spanning Tree Groups
PVRST is based on IEEE 802.1w Rapid Spanning Tree Protocol (RSTP). Like RSTP, PVRST mode
provides rapid Spanning Tree convergence. However, similar to the way standard STP is enhanced
by PVST+ (see
“Per-VLAN Spanning Tree Groups” on page 117 ), PVRST is enhanced to allow
per-VLAN STGs on the switch.
In PVRST mode, each VLAN may be assigned to one of 128 STGs, with each STG acting as an
independent, simultaneous instance of STP. PVRST uses IEEE 802.1Q tagging to differentiate STP
BPDUs.
PVRST mode is compatible with Cisco R-PVST/R-PVST+.
Configuring PVRST
This configuration shows how to configure PVRST for VLAN 1 assigned to STG 1, and VLAN2
assigned to STG 2.
1. Set the Spanning Tree mode to PVRST.
2. Configure port membership for each VLAN, then define the STGs for each VLAN.
By default, port 1 is a member of VLAN 1, which automatically assigned to STG 1, so no additional
configuration is required for STG 1. However, for STG 2, port 2 if first added to VLAN 2, and then
VLAN 2 is assigned to STG 2.
RS G8124(config)# spanning-tree mode pvrst
RS G8124(config)# vlan 2
RS G8124(config-vlan)# enable
RS G8124(config-vlan)# member 2
RS G8124(config-vlan)# stg 2
RS G8124(config-vlan)# exit