Spanning-tree root-guard, Spanning-tree spanning-disabled, Spanning-tree spanning-disabled (354) – Brocade Communications Systems Brocate Ethernet Access Switch 6910 User Manual
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Brocade 6910 Ethernet Access Switch Configuration Guide
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Spanning Tree Commands
18
spanning-tree root-guard
This command prevents a designated port
9
from taking superior BPDUs into account and allowing
a new STP root port to be elected. Use the no form to disable this feature.
Syntax
[no] spanning-tree root-guard
Default Setting
Disabled
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
•
A bridge with a lower bridge identifier (or same identifier and lower MAC address) can take over
as the root bridge at any time.
•
When Root Guard is enabled, and the switch receives a superior BPDU on this port, it is set to
the Discarding state until it stops receiving superior BPDUs for a fixed recovery period. While in
the discarding state, no traffic is forwarded across the port.
•
Root Guard can be used to ensure that the root bridge is not formed at a suboptimal location.
Root Guard should be enabled on any designated port connected to low-speed bridges which
could potentially overload a slower link by taking over as the root port and forming a new
spanning tree topology. It could also be used to form a border around part of the network where
the root bridge is allowed.
•
When spanning tree is initialized globally on the switch or on an interface, the switch will wait
for 20 seconds to ensure that the spanning tree has converged before enabling Root Guard.
Example
Console(config)#interface ethernet 1/5
Console(config-if)#spanning-tree edge-port
Console(config-if)#spanning-tree root-guard
Console(config-if)#
spanning-tree spanning-disabled
This command disables the spanning tree algorithm for the specified interface. Use the no form to
re-enable the spanning tree algorithm for the specified interface.
Syntax
[no] spanning-tree spanning-disabled
Default Setting
Enabled
Command Mode
Interface Configuration (Ethernet, Port Channel)
9. See Port Role under