Siemens SCALANCE W780 Configuration Manual page 261

Description
Table 1 has the following columns:
● Column 1
Shows that the settings are valid for all ports of table 2.
● MSTP Status
Select the setting for all ports from the drop-down list. If "No Change" is selected, the
entries of the corresponding column in Table 2 remain unchanged.
● Copy to Table
If you click the button, the setting is adopted for all ports of table 2.
The page contains the following box:
● "MSTP Instance ID" drop-down list
In the drop-down list, select the ID of the MSTP instance.
Table 2 has the following columns:
● Port
Shows all available ports and interfaces.
● MSTP Instance ID
ID of the MSTP instance.
● MSTP Status
Click the check box to enable or disable this option.
● Priority
Enter the priority of the port. The priority is only evaluated when the path costs are the
same.
The value must be divisible by 16. If the value that cannot be divided by 16, the value is
automatically adapted.
Range of values: 0 - 240.
The default is 128.
● Cost Calc
Enter the path cost calculation in the input box. If you enter the value "0" here, the
automatically calculated value is displayed in the next box "Path Cost".
● Path Cost
The path costs from this port to the root bridge. The path with the lowest value is selected
as the path. If several ports of a device have the same value, the port with the lowest port
number is selected.
If the value in the "Cost Calc" field is "0", the automatically calculated value is displayed.
Otherwise, the value of the "Cost Calc" field is displayed.
The calculation of the path costs is largely based on the transmission speed. The higher
the achievable transmission rate, the lower the value for the path costs will be.
Typical values for rapid spanning tree are as follows:
– 1000 Mbps = 20,000
– 100 Mbps = 200,000
– 10 Mbps = 2,000,000
The values can, however, also be set individually.
SCALANCE W780/W740 to IEEE 802.11n Web Based Management
Configuration Manual, 03/2015, C79000-G8976-C267-08
Configuring with Web Based Management
5.7 "Layer 2" menu
261