Allied Telesis AT-S95 CLI - Manual (Page 228)

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Allied Telesis
Command Line Interface User’s Guide
spanning-tree guard root
The spanning-tree guard root Interface Configuration (Ethernet, port-channel) mode command enables 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 root guard on the interface.
Syntax
spanning-tree guard root
no spanning-tree guard root
Default Configuration
Root guard is disabled.
Command Mode
Interface Configuration (Ethernet, port-channel) mode
User Guidelines
Root guard can be enabled when the device operates in STP, RSTP and MSTP.
When root guard is enabled, the port changes to the alternate state if spanning-tree calculations selects the port
as the root port.
Example
eThe following example prevents Ethernet port 1/g1 from being the root port of the device.
spanning-tree bpduguard
The spanning-tree bpduguard Interface Configuration (Ethernet, port-channel) mode command shutsdown an
interface when it receives a bridge protocol data unit (BPDU). Use the no form of this command to restore the
default configuration.
Syntax
spanning-tree bpduguard
no spanning-tree bpduguard
Default Configuration
The default configuration is set to disabled.
Command Mode
Interface Configuration (Ethernet, port-channel) mode
User Guidelines
You can enable the command when the spanning tree is enabled (useful when the port is in the PortFast mode) or
disabled.
Console(config) # interface ethernet 1/g1
Console(config-mst) # spanning-tree guard root