Users Guide

Enabling Portfast BPDU guard and loop guard at the same time on a port results in a port that remains in a
Blocking state and prevents trac from owing through it. For example, when Portfast BPDU guard and loop
guard are both congured:
• If a BPDU is received from a remote device, BPDU guard places the port in an Err-Disabled Blocking state and
no trac is forwarded on the port.
• If no BPDU is received from a remote device, loop guard places the port in a Loop-Inconsistent Blocking state
and no trac is forwarded on the port.
Example
DellEMC(conf-if-te-1/1)# spanning-tree pvst vlan 3 cost 1800
DellEMC(conf-if-te-1/1)# end
DellEMC(conf-if-te-1/1)# show config
!
interface TenGigabitEthernet 1/1
no ip address
switchport
spanning-tree pvst vlan 3 cost 1800
no shutdown
DellEMC(conf-if-te-1/1)# end
DellEMC#
Related Commands
• show spanning-tree pvst — views the PVST+ conguration.
spanning-tree pvst err-disable
Place ports in an Err-Disabled state if they receive a PVST+ BPDU when they are members an untagged VLAN.
S4048
Syntax
spanning-tree pvst err-disable cause invalid-pvst-bpdu
Defaults Enabled; ports are placed in the Err-Disabled state if they receive a PVST+ BPDU when they are members of an
untagged VLAN.
Command Modes INTERFACE
Command History
This guide is platform-specic. For command information about other platforms, see the relevant Dell EMC
Networking OS Command Line Reference Guide.
Version Description
9.10(0.1) Introduced on the S6010-ON and S4048T-ON.
9.10(0.0) Introduced on the S3148.
9.10(0.0) Introduced on the S6100-ON.
9.8(2.0) Introduced on the S3100 series.
9.8(1.0) Introduced on the Z9100-ON.
9.8(0.0P5) Introduced on the S4048-ON.
9.8(0.0P2) Introduced on the S3048-ON.
9.7(0.0) Introduced on the S6000-ON.
1454 Per-VLAN Spanning Tree Plus (PVST+)