configuration messages at regular intervals. Any port that ages out STP information (provided in the last configuration message) becomes the designated port for the attached LAN. If it is a root port, a new root port is selected from among the switch ports attached to the network. (Note that references to “ports” in this section mean “interfaces,” which includes both ports and trunks.)
Minimum: The higher of 6 or [2 x (Hello Time + 1)]
Maximum: The lower of 40 or [2 x (Forward Delay - 1)]
Default: 20
■Hello Time - The interval (in seconds) at which the root switch transmits a configuration message. Default: 2
Minimum: 1
Maximum: The lower of 10 or [(Max. Message Age / 2)
■Forward Delay - The maximum time (in seconds) this switch will wait before changing states (i.e., discarding to learning to forwarding). This delay is required because every switch 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.
Minimum: The higher of 4 or [(Max. Message Age / 2) + 1]
Maximum: 30
Default: 15
■Root Priority - The priority of the switch in the Spanning Tree that this switch has accepted as the root switch.
■Root MAC Address - The MAC address of the switch in the Spanning Tree that this switch has accepted as the root switch.
■Root Path Cost - The path cost from the root port on this switch to the root switch.
■Root Port - The number of the port on this switch that is closest to the root. This switch communicates with the root switch through this port. If there is no root port, then this switch has been accepted as the root switch of the Spanning Tree network.
■Root Maximum Age - The maximum time (in seconds) this switch can wait without receiving a configuration message before attempting to reconfigure. All switch 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 switch ports attached to the network. (References to “ports” in this section means “interfaces,” which includes both ports and trunks.)
■Root Hello Time - The interval (in seconds) at which this switch transmits a configuration message.
■Root Forward Delay - The maximum time (in seconds) this switch will wait before changing states (i.e., discarding to learning to forwarding). This delay is required because every switch 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.
■Topology Changes — The number of times the Spanning Tree has been reconfigured.
■Last Topology Change Time - The time since the Spanning Tree was last reconfigured.
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