D-Link DES-3326 User Manual - Spanning Tree Protocol
DES-3326 Layer 3 Fast Ethernet Switch User’s Guide
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Switch Management and Operating Concepts
source, a destination, or either (switch must be in IP
Routing mode).
Spanning Tree Protocol
The IEEE 802.1D Spanning Tree Protocol allows for the blocking of
links between switches that form loops within the network. When
multiple links between switches are detected, a primary link is
established. Duplicated links are blocked from use and become
standby links. The protocol allows for the duplicate links to be
used in the event of a failure of the primary link. Once the
Spanning Tree Protocol is configured and enabled, primary links
are established and duplicated links are blocked automatically.
The reactivation of the blocked links (at the time of a primary link
failure) is also accomplished automatically – without operator
intervention.
This automatic network reconfiguration provides maximum uptime
to network users. However, the concepts of the Spanning Tree
Algorithm and protocol are a complicated and complex subject and
must be fully researched and understood. It is possible to cause
serious degradation of the performance of the network if the
Spanning Tree is incorrectly configured. Please read the following
before making any changes from the default values.
The DES-3326 STP allows two levels of spanning trees to be
configured. The first level constructs a spanning tree on the links
between switches. This is referred to as the Switch or Global
level. The second level is on a port group basis. Groups of ports
are configured as being members of a spanning tree and the
algorithm and protocol are applied to the group of ports. This is
referred to as the Port or VLAN level.
The DES-3326 switch STP performs the following functions: