Spanning Tree : STP Status and Global Settings
 
STP Status and Global Settings
The STP Status and Global Settings page contains parameters for enabling STP, RSTP, or MSTP.
Use the STP Interface Settings page, RSTP Interface Settings page, and MSTP Properties page to configure each mode, respectively.
To set the STP status and global settings:
STEP 1 Click Spanning Tree > STP Status & Global Settings.
STEP 2 Enter the parameters.
Global Settings:
Spanning Tree State—Select to enable on the device.
STP Loopback Guard—Select to enable Loopback Guard on the device.
STP Operation Mode—Select an STP mode.
BPDU Handling—Select how Bridge Protocol Data Unit (BPDU) packets are managed when STP is disabled on the port or the device. BPDUs are used to transmit spanning tree information.
- Filtering—Filters BPDU packets when Spanning Tree is disabled on an interface.
- Flooding—Floods BPDU packets when Spanning Tree is disabled on an interface.
Path Cost Default Values—Selects the method used to assign default path costs to the STP ports. The default path cost assigned to an interface varies according to the selected method.
- Short—Specifies the range 1 through 65,535 for port path costs.
- Long—Specifies the range 1 through 200,000,000 for port path costs.
Bridge Settings:
Priority—Sets the bridge priority value. After exchanging BPDUs, the device with the lowest priority becomes the Root Bridge. In the case that all bridges use the same priority, then their MAC addresses are used to determine the Root Bridge. The bridge priority value is provided in increments of 4096. For example, 4096, 8192, 12288, and so on.
Hello Time—Set the interval (in seconds) that a Root Bridge waits between configuration messages.
Max Age—Set the interval (in seconds) that the device can wait without receiving a configuration message, before attempting to redefine its own configuration.
Forward Delay—Set the interval (in seconds) that a bridge remains in a learning state before forwarding packets. For more information, refer to STP Interface Settings.
Designated Root:
Bridge ID—The bridge priority concatenated with the MAC address of the device.
Root Bridge ID—The Root Bridge priority concatenated with the MAC address of the Root Bridge.
Root Port—The port that offers the lowest cost path from this bridge to the Root Bridge. (This is significant when the bridge is not the root.)
Root Path Cost—The cost of the path from this bridge to the root.
Topology Changes Counts—The total number of STP topology changes that have occurred.
Last Topology Change—The time interval that elapsed since the last topology change occurred. The time appears in a days/hours/minutes/seconds format.
STEP 3 Click Apply. The STP Global settings are written to the Running Configuration file.