Motorola EX-3524, Cli Reference Manual

Page: 379 / 617

Chapter 16
| Spanning Tree Commands
– 379 –
conjunction with edge ports which should only connect end stations to the
switch, and therefore do not need to process BPDUs. However, note that if a
trunking port connected to another switch or bridging device is mistakenly
configured as an edge port, and BPDU filtering is enabled on this port, this
might cause a loop in the spanning tree.
◆
Before enabling BPDU Filter, the interface must first be configured as an edge
port with the
spanning-tree edge-port command.
Example
Console(config)#interface ethernet 1/5
Console(config-if)#spanning-tree edge-port
Console(config-if)#spanning-tree bpdu-filter
Console(config-if)#
Related Commands
spanning-tree edge-port (381)
spanning-tree
bpdu-guard
This command shuts down an edge port (i.e., an interface set for fast forwarding) if
it receives a BPDU. Use the
no form to disable this feature.
Syntax
[ no ] spanning-tree bpdu-guard
Default Setting
Disabled
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
◆
An edge port should only be connected to end nodes which do not generate
BPDUs. If a BPDU is received on an edge port, this indicates an invalid network
configuration, or that the switch may be under attack by a hacker. If an
interface is shut down by BPDU Guard, it must be manually re-enabled using
the
no spanning-tree spanning-disabled command.
◆
Before enabling BPDU Guard, the interface must be configured as an edge port
with the
spanning-tree edge-port command. Also note that if the edge port
attribute is disabled on an interface, BPDU Guard will also be disabled on that
interface.