Accton Technology ES4548D, ES4524D, 24/48-Port manual 22-4

22 Spanning Tree Algorithm Configuration

These additional parameters are only displayed for the CLI:

•Spanning tree mode – Specifies the type of spanning tree used on this switch:

-STP: Spanning Tree Protocol (IEEE 802.1D)

-RSTP: Rapid Spanning Tree (IEEE 802.1w)

-MSTP: Multiple Spanning Tree (IEEE 802.1s)

•Instance – Instance identifier of this spanning tree. (This is always 0 for the CIST.)

•VLANs configuration – VLANs assigned to the CIST.

•Priority – Bridge priority is used in selecting the root device, root port, and designated port. The device with the highest priority (i.e., lower numeric value) becomes the STA root device. However, if all devices have the same priority, the device with the lowest MAC address will then become the root device.

•Root Hello Time – Interval (in seconds) at which this device transmits a configuration message.

•Root Maximum Age – The maximum time (in seconds) this device can wait without receiving a configuration message before attempting to reconfigure. All device ports (except for designated ports) should receive configuration messages at regular intervals. If the root port ages out STA information (provided in the last configuration message), a new root port is selected from among the device ports attached to the network. (References to “ports” in this section means “interfaces,” which includes both ports and trunks.)

•Root Forward Delay – The maximum time (in seconds) this device will wait before changing states (i.e., discarding to learning to forwarding). This delay is required because every device must receive information about topology changes before it starts to forward frames. In addition, each port needs time to listen for conflicting information that would make it return to a discarding state; otherwise, temporary data loops might result.

•Max hops – The max number of hop counts for the MST region.

•Remaining hops – The remaining number of hop counts for the MST instance.

•Transmission limit – The minimum interval between the transmission of consecutive RSTP/MSTP BPDUs.

•Path Cost Method – The path cost is used to determine the best path between devices. The path cost method is used to determine the range of values that can be assigned to each interface.

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