Siemens SIMATIC NET SCALANCE S615 Configuration Manual page 102

Configuring with Web Based Management
4.4 "Information" menu
● Root Port
Shows the port via which the switch communicates with the root bridge.
● Root Cost
The path costs from this device to the root bridge.
● Topology Changes / Last Topology Change
The entry for the device shows the number of reconfiguration actions due to the spanning
tree mechanism since the last startup. For the root bridge, the time since the last
reconfiguration is displayed as follows:
– Seconds: Supplement "sec" after the number
– Minutes: Supplement "min" after the number
– Hours: Supplement "hr" after the number
● Bridge Hello Time / Root Hello Time
Each bridge sends configuration frames (BPDUs) regularly. The interval between two such
frames is the Hello time. The default for this parameter is 2 seconds.
● Bridge Forward Delay / Root Forward Delay
New configuration information is not used immediately by a bridge but only after the
forwarding delay specified in the parameter. This ensures that operation is only started with
the new topology after all the bridges have the required information. The default for this
parameter is 15 seconds.
● Bridge Max Age / Root Max Age
When the max age timer elapses the received BPDU is discarded to be accepted as valid
by the switch. The default value is 20s.
● Bridge Max Hop Count
This parameter specifies how many MSTP nodes a BPDU may pass through. If an MSTP
BPDU is received and has a hop count that exceeds the value configured here, it is
discarded. The default for this parameter is 20.
● Root Hop Count
The number of nodes that need to be run through on the way to the root bridge.
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SCALANCE S615 Web Based Management
Configuration Manual, 11/2019, C79000-G8976-C388-08