Reference Guide

Per-VLAN Spanning Tree Plus (PVST+) | 403
23
Per-VLAN Spanning Tree Plus (PVST+)
Overview
Per-VLAN spanning tree plus (PVST+) is a variation of spanning tree—developed by a third party—that
allows you to configure a separate spanning tree instance for each VLAN (Figure 23-1). For more
information about spanning tree, refer to Spanning Tree Protocol (STP).
Figure 23-1. Per-VLAN Spanning Tree
R2
R3
R1
2/32
1/22
1/32
2/12
3/22
3/12
STI 3: VLAN 300
STI 1: VLAN 100
STI 2: VLAN 200STI 2: VLAN 200
Forwarding
X
X
X
X
X
X
STI 1/2/3 root
Blocking