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 traffic from flowing through it. For example, when Portfast BPDU guard
and loop guard are both configured:
• If a BPDU is received from a remote device, BPDU guard places the port in an Err-Disabled Blocking
state and no traffic 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 traffic is forwarded on the port.
Example
Dell(conf-if-te-1/1)# spanning-tree pvst vlan 3 cost 1800
Dell(conf-if-te-1/1)# end
Dell(conf-if-te-1/1)# show config
!
interface TenGigabitEthernet 1/1
no ip address
switchport
spanning-tree pvst vlan 3 cost 1800
no shutdown
Dell(conf-if-te-1/1)# end
Dell#
Related
Commands
• show spanning-tree pvst — views the PVST+ configuration.
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.
S4820T
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-specific. For command information about other platforms, see the relevant Dell
Networking OS Command Line Reference Guide.
Version Description
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.
9.2(1.0) Introduced on the Z9500.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
8.3.11.1 Introduced on the Z9000.
8.3.7.0 Introduced on the S4810.
Per-VLAN Spanning Tree Plus (PVST+) 1287