User's Manual

Configuration Using Web Based Management and the Command Line Interface
Age of the Configuration Information
With the Max Age parameter, you specify the maximum age of configuration infor-
mation. If a bridge receives configuration information older than specified in Max
Age, it discards the message and starts a new calculation of the paths.
New configuration data is not used immediately by a bridge but only after the pe-
riod specified in the Forward Delay parameter. This ensures that operation is only
started with the new topology after all the bridges have the required information.
Configuration
Select the Enable Spanning Tree check box if you want to use the spanning tree
algorithm. If necessary, modify the following parameters to specify how the span-
ning tree algorithm operates:
● Bridge Priority
You can enter a value between 0 and 65535. A suitable setting is 32768. You
can assign the same priority to several computers, however, such computers do
not normally become the root bridge.
● Hello Time
A valid value is between 1 and 10 seconds. A time of 2 seconds is recom-
mended. Shortening this time makes the protocol more robust particularly if
configuration packets are lost. If the Hello Time is set to higher values, this re-
duces the effort required for the algorithm because configuration packets are
sent less frequently.
● Max Age
A valid value is between 6 and 40 seconds. A time of 20 seconds is recom-
mended. If the value for Max Age is set too low, the paths are recalculated un-
necessarily when there are temporary breaks on connections.
● Forward Delay
A valid value is between 4 and 30 seconds. A time of 15 seconds is recom-
mended. If the value is too low, some bridges do not yet have up-to-date con-
figuration information and this leads to a recalculation of the topology. A higher
value leads to longer pauses following reconfiguration.
● Priority
With this parameter, you specify the priority of the ports of a bridge. With the
SCALANCE W 788, you can specify the priority of the Ethernet interface and
the wireless interface. You can specify values between 0 and 255. The default
is 128.
Operating Instructions SCALANCE W 788-1pro / SCALANCE W 788-2pro
94 C79000-G8976-C184-01