SMC Networks SMC6824M manual 157

SPANNING TREE ALGORITHM CONFIGURATION

•Forward Delay – The maximum time (in seconds) the root 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.

•Designated Root – The priority and MAC address of the device in the Spanning Tree that this switch has accepted as the root device.

-Root Port – The number of the port on this switch that is closest to the root. This switch communicates with the root device through this port. If there is no root port, then this switch has been accepted as the root device of the Spanning Tree network.

-Root Path Cost – The path cost from the root port on this switch to the root device.

•Configuration Changes – The number of times the Spanning Tree has been reconfigured.

•Last Topology Change – Time since the Spanning Tree was last reconfigured.

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)

•Spanning tree backup root – Automatically lowers the switch’s bridge priority by 4096 if it loses contact with the current root device. To succeed, the switch must have a direct connection to current root bridge, and its adjusted bridge priority must be higher (i.e., a numerically lower value) than all the other bridges in the spanning tree.

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

•VLANs configuration – VLANs assigned to the CIST.

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