Users Guide

• When you add a physical port to a port channel already in the Error Disable state, the new member port is also disabled in the
hardware.
• When you remove a physical port from a port channel in the Error Disable state, the Error Disabled state is cleared on this physical port
(the physical port is enabled in the hardware).
• You can clear the Error Disabled state with any of the following methods:
○ Perform a shutdown command on the interface.
○ Disable the shutdown-on-violation command on the interface (the no spanning-tree stp-id portfast
[bpduguard | [shutdown-on-violation]] command).
○ Disable spanning tree on the interface (the no spanning-tree command in INTERFACE mode).
○ Disabling global spanning tree (the no spanning-tree in CONFIGURATION mode).
Figure 125. Enabling BPDU Guard
Dell Networking OS Behavior: BPDU guard and BPDU filtering both block BPDUs, but are two separate features.
BPDU guard:
• is used on edgeports and blocks all traffic on edgeport if it receives a BPDU.
• drops the BPDU after it reaches the RP and generates a console message.
BPDU filtering:
• disables spanning tree on an interface
• drops all BPDUs at the line card without generating a console message
Example of Blocked BPDUs
Dell(conf-if-te-1/7)#do show spanning-tree rstp brief
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 32768, Address 0001.e805.fb07
Root Bridge hello time 2, max age 20, forward delay 15
Bridge ID Priority 32768, Address 0001.e85d.0e90
Configured hello time 2, max age 20, forward delay 15
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
---------- -------- ---- ------- --- ------- --------------------
778
Spanning Tree Protocol (STP)