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(Rapid) Spanning Tree
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5.1.5.6 Flowchart for specifying the root path
Figure 5-14 Flowchart for specifying the root path
5.1.5.7 Extended configuration
It may be practical to actively specify the topology that forms from the Spanning Tree
protocol and not to leave it to the random MAC addresses of the switches involved.

Non-blocking/blocking data paths can thus be influenced and a load distribution specified.

It may also be practical to explicitly deactivate the Spanning Tree protocol at those ports that
do not participate in Spanning Tree so as to benefit from the fast forwarding function.

The Spanning Tree protocol also must be deactivated at individual ports if two different
network segments - both using Spanning Tree - are to be coupled via these ports without
the two tree structures melting to a large Spanning Tree.
Specifying the root switch
The root switch is assigned via the assignment of an appropriate priority for the Spanning
Tree segment. Set the highest priority (lowest value) in the “Priority” field on the “STP Bridge
Configuration” page in WBM for the switch selected as the root switch. Make sure that all
the other network switches have a lower priority (higher value). Here, the set path costs are
not evaluated.
Specifying the root port or designated port
The root port and designated port are always the ports with the lowest path costs. If the
costs are the same, the priority is the decisive criterion. If the priorities are also the same,
the port number is the decisive criterion. Specify an appropriate combination of costs and
Pfad zum
Root-Switch ermitteln
Gleiche
Pfadkosten?
Gleiche Priorität der
Switches?
Gleiche Priorität
der einzelnen Ports?
Geringste Pfadkosten
Root-Pfad
Höchste Priorität des
Switches Root-Pfad
Höchste Priorität des
Ports Root-Pfad
Kleinste Port-Nummer
Root-Pfad
Pfad zum
Root-Switch ist festgelegt
ja
ja
ja
nein
nein
nein
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