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Spanning Tree
The
Spanning Tree
page contains links to pages that allow you to specify the parameters of the Spanning Tree Protocol:
l
Bridge Settings
l
Port Settings
l
Trunk Settings
Bridge Settings
The
Bridge Settings
page contains the following information:
l
Bridge ID
—
Identifies a unique identifier for the switch in the Spanning Tree. The ID is calculated using the defined Spanning Tree priority of the switch
and its MAC address. The lower the Bridge ID, the more likely the switch will act as the root.
l
Max Age
—
Specifies the maximum time (in seconds) that the switch waits before attempting to reconfigure (if it has not received a configuration
message).
l
Hello Time
—
Specifies the time interval (in seconds) at which the root device transmits a configuration message.
l
Forward Delay
—
Specifies the maximum time (in seconds) the root device waits before changing states (from listening to learning to forwarding).
l
Designated Root
—
Identifies the priority and MAC address of the device in the Spanning Tree that the switch has accepted as the root device.
l
Root Port
—
Specifies the port number on the switch that is closest to the root. The switch communicates with the root device through this port. If there
is no root port, the switch has been accepted as the root device of the Spanning Tree network.
l
Root Path Cost
—
Identifies the path cost from the root port on the switch to the root device.
l
Configuration Changes
—
Specifies the number of times the Spanning Tree has been reconfigured.
l
Last Topology Change
—
Identifies the time since the Spanning Tree was last reconfigured.
From the
Bridge Settings
page, under
Attributes
, you can also enable and configure the following Spanning Tree parameters:
l
Spanning Tree State
—
Enables or disables the Spanning Tree. If you enable the Spanning Tree, you must complete the other fields.
l
Priority
—
Sets the priority setting among other switches in the Spanning Tree. (The range is 0 to 65535.)
l
Hello Time
—
Sets the interval between configuration messages sent by the Spanning Tree Protocol. (The range is 1 to 10 seconds.)
l
Maximum Age
—
Sets the amount of time before the system discards a configuration message. (The range is 6 to 40 seconds.)
l
Forward Delay
—
Sets the amount of time the system spends in
learning
and
listening
states. (The range is 4 to 30 seconds.)
To save any changes you make in this page, click
Apply Changes
. If you don't want to save the changes, click
Refresh
.
CLI Commands
The following table summarizes the equivalent CLI commands for items in the
Spanning Tree/Bridge Settings
page.
Command
Usage
bridge
bridge-group
spanning-tree
Enables the spanning tree algorithm globally for the switch.
Use the
no form
command to disable it.
bridge
bridge-group
forward-time
seconds
Configures the spanning tree bridge forward time globally for the
switch.
bridge
bridge-group
hello-time
time
Configures the spanning tree bridge hello time globally for the
switch.