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DES-3200-10/18/28/28F Layer 2 Ethernet Managed Switch User Manual
NOTE: The Hello Time cannot be longer than the Max. Age. Otherwise, a
configuration error will occur. Observe the following formulas when setting
the above parameters:
Max. Age ≤ 2 x (Forward Delay - 1 second)
Max. Age ≥ 2 x (Hello Time + 1 second)
STP Port Settings
STP can be set up on a port per port basis.
To view the following window, click L2 Features > Spanning Tree > STP Port Settings:
Figure 3 - 42. STP Port Settings window
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 based on 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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