The Spanning Tree Protocol; The Tasks Of The Stp - Hirschmann RS40 User Manual

Rapid Spanning Tree

4.1 The Spanning Tree Protocol

Because RSTP is a further development of the STP, all the following descrip-
tions of the STP also apply to the RSTP.

4.1.1 The tasks of the STP

The Spanning Tree Algorithm reduces network topologies that are set up
using bridges, and that have ring structures with redundant connections, to a
tree structure. In doing this, STP divides up the ring structures on the basis
of specified rules by deactivating redundant paths. If a path is interrupted by
mistake, the STP reactivates the path just deactivated. This enables
redundant connections for increased data safety.
In forming the tree structure, the STP determines what is known as a root
bridge. This forms the basis of the STP tree structure.
Features of the STP algorithm:
automatic reconfiguration of the tree structure in the case of a bridge error
or the interruption of a data path
the tree structure is stabilized up to the maximum network size (up to 39
hops, depending on the setting for "Max. Age")
stabilization is effected within a brief, specified period
topology can be specified and reproduced by the management
transparency for the terminal devices
low network load relative to the available transmission capacity due to the
tree structure created
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4.1 The Spanning Tree Protocol
Redundancy L2E
Release 4.1 03/08