Cisco 300 Series

Spanning-Tree Commands
OL-32830-01 Command Line Interface Reference Guide 900
46
Syntax
spanning-tree bpdu
{filtering | flooding}
no spanning-tree bpdu
Parameters
• filtering—Specifies that BPDU packets are filtered when the spanning tree
is disabled on an interface.
• flooding—Specifies that untagged BPDU packets are flooded
unconditionally (without applying VLAN rules) to ports with the spanning
tree disabled and BPDU handling mode of flooding. Tagged BPDU packets
are filtered.
Default Configuration
The spanning-tree bpdu (Global) command determines the default configuration.
Command Mode
Interface (Ethernet, Port Channel) Configuration mode
Example
The following example defines the BPDU packet as flooding when the spanning
tree is disabled on
gi1 3.
switchxxxxxx(config)# interface gi1 3
switchxxxxxx(config-if)# spanning-tree bpdu flooding
46.15 spanning-tree guard root
use the spanning-tree guard root Interface (Ethernet, Port Channel) Configuration
mode command to enable Root Guard on all spanning-tree instances on the
interface. Root guard prevents the interface from becoming the root port of the
device. Use the no form of this command to disable the root guard on the interface.
Syntax
spanning-tree guard root
no spanning-tree guard root