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D-Link DGS-3212SR Layer 2 Gigabit Ethernet Switch
STP Port Settings
For stacked switch installations, first select the Unit to be configured.
Figure 10-2. STP Port Settings
In addition to setting Spanning Tree parameters for use on the switch level, the switch allows for the
configuration of groups of ports, each port-group of which will have its own spanning tree, and will require some
of its own configuration settings. An STP Group will use the switch-level parameters entered above, with the
addition of Port Priority and Port Cost.
An STP Group spanning tree works in the same way as the switch-level spanning tree, but the root bridge
concept is replaced with a root port concept. A root port is a port of the group that is elected on the basis of port
priority and port cost, to be the connection to the network for the group. Redundant links will be blocked, just as
redundant links are blocked on the switch level.
The STP on the switch level blocks redundant links between switches (and similar network devices). The port
level STP will block redundant links within an STP Group.
It is advisable to define an STP Group to correspond to a VLAN group of ports.
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