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Figure 120. Enabling BPDU Guard
Dell Networking OS Behavior: BPDU guard and BPDU filtering (refer to Removing an Interface from the Spanning Tree
Group) 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.
Example of Blocked BPDUs
Dell#show spanning-tree 0 brief
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 32768, Address 0001.e88a.fdb3 Cost 1
Root Port 2 (Port-channel 1)
Root Bridge hello time 2, max age 20, forward delay 15
Bridge ID Priority 32768, Address 001e.c9f1.00cf
Configured hello time 2, max age 20, forward delay 15
Bpdu filter disabled globally
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
---------- ------- ---- ------ ----------- ------ ------ ------
Po 1 8.2 8 1 FWD 0 32768 0001.e88a.fdb3 8.2
Te 3/20 8.317 8 4 EDS 1 32768 001e.c9f1.00cf 8.317
Te 4/20 8.373 8 4 FWD 1 32768 001e.c9f1.00cf 8.373
Te 4/21 8.374 8 4 FWD 1 32768 001e.c9f1.00cf 8.374
Dell#show ip int br ten 3/20
Interface IP-Address OK Method Status Protocol
TenGigabitEthernet 3/20 unassigned YES None up up
Dell#
Global BPDU Filtering
When BPDU Filtering is enabled globally, it stops transmitting BPDUs on the operational port fast enabled ports by default.
When it receives BPDUs, it automatically participates in the spanning tree. By default global bpdu filtering is disabled.
Spanning Tree Protocol (STP)
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