Niveo Professional NGS16TP - Manual (Page 99)

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NIVEO PROFESSIONAL Gigabit Management Switch
User's Manual
6.4.6 Spanning Tree
Spanning Tree Protocol can prevent traffic looping in network. It can be configured for
switch unit (bridge) and port unit. If spanning tree function is enabled, any link down to
link up will have several seconds delay for the port going to forwarding state.
[Setting of Bridge]
Here are the parameters for Spanning Tree operation on the switch.
Enable/Disable : enable/disable spanning tree operation
Force Version : It will operate as Rapid Spanning Tree in “Normal” state. And it can be
forced to operate at old Spanning Tree mode if “Compatible with old STP” is selected.
Bridge Priority (0~61440) : Bridge priority is for selecting the root device, root port, and
designated port. The device with the highest priority (lowest value) becomes the STA
root device. If all devices have the same priority, the device with the lowest MAC
address will then become the root device.
Hello Time (1~10) : the period to send the spanning tree maintenance packet if the
switch is the root of the spanning tree. Default is 2 seconds.
Maximum Age (6~40) : the spanning tree aging time if no spanning tree maintenance
packet is received. It will cause the spanning tree to re-create. Default is 20 seconds.
Forward Delay (4~30): the maximum waiting time before changing states (i.e., learning
to forwarding). This delay is required because every device must receive information
about topology changes before it starts to forward frames. In addition, each port needs
time to listen for conflicting information that would make it return to a blocking state;
otherwise, temporary data loops might result.
The parameters have relation with each other. And here is the rule for it.
2*(Hello Time +1) is less or equal to Maximum Age, and Maximum Age is less or equal to
2*(Forward Delay -1).
[Setting of Port]