Reference Guide

Per-VLAN Spanning Tree plus (PVST+) | 1167

extend system-id

c e s

Use Extend System ID to augment the Bridge ID with a VLAN ID so that PVST+ differentiate

between BPDUs for each VLAN. If for some reason on VLAN receives a BPDU meant for another

VLAN, PVST+ will then not detect a loop, and both ports can remain in forwarding state.

Syntax

extend system-id

Defaults

Disabled

Command Modes

PROTOCOL PVST

Command

History

Example

FTOS(conf-pvst)#do show spanning-tree pvst vlan 5 brief

VLAN 5

Executing IEEE compatible Spanning Tree Protocol

Root ID Priority 32773, Address 0001.e832.73f7

Root Bridge hello time 2, max age 20, forward delay 15

Bridge ID Priority 32773 (priority 32768 sys-id-ext 5), Address 0001.e832.73f7

We are the root of Vlan 5

Configured hello time 2, max age 20, forward delay 15

Interface Designated

Name PortID Prio Cost Sts Cost Bridge ID PortID

---------- -------- ---- ------ --- ------- -------------------- --------

Gi 0/10 128.140 128 200000 FWD 0 32773 0001.e832.73f7 128.140

Gi 0/12 128.142 128 200000 DIS 0 32773 0001.e832.73f7 128.142

Interface

Name Role PortID Prio Cost Sts Cost Link-type Edge

---------- ------ -------- ---- ------- --- ------- --------- ------------------------

Gi 0/10 Desg 128.140 128 200000 FWD 0 P2P No

Gi 0/12 Dis 128.142 128 200000 DIS 0 P2P No

Commands

Version 8.3.1.0 Introduced

protocol spanning-tree pvst Enter SPANNING TREE mode on the switch.