Instruction Manual
70
User-Changeable STP Parameters
The switch’s factory default setting should cover the majority of installations.
However, it is advisable to keep the default settings as set at the factory, unless
absolutely necessary to change. The user-changeable parameters in the switch
are as follows:
•
Priority:
A priority for the switch can be set from 0 to 65535. 0 is equal to
the highest priority.
•
Hello Time:
The
Hello Time
can be from 1 to 10 seconds. This is the interval
between two transmissions of BPDU packets sent by the Root Bridge to tell
all other Switches that it is indeed the Root Bridge. If you set a Hello Time for
your Switch, and it is not the Root Bridge, the set
Hello Time
will be used if
and when your Switch becomes the Root Bridge.
Note:
The
Hello Time
cannot be longer than the
Max. Age
. Otherwise, a
configuration error will occur.
•
Max. Age:
The
Max. Age
can be from 6 to 40 seconds. At the end of the
Max. Age
, if a BPDU has still not been received from the Root Bridge, the
Switch will start sending its own BPDU to all other Switches for permission
to become the Root Bridge. If it turns out that your Switch has the lowest
Bridge Identifier, it will become the Root Bridge.
•
Forward Delay Timer:
The
Forward Delay Timer
can be from 4 to 30
seconds. This is the time any port on the Switch spends in the listening state
while moving from the blocking state to the forwarding state.
Note:
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)
•
Port Priority:
Port Priority can be from 0 to 240. The lower the number, the
greater the probability the port will be chosen as the Root Port.
•
Port Cost:
Port Cost can be set from 0 to 200000000. The lower the number,
the greater the probability the port will be chosen to forward packets.
STP Global Settings
This page allows you to configure STP system settings. The settings are used by all
STP Bridge instances in the Switch. The Managed Switch supports the following
Spanning Tree protocols:
•
Compatible -- Spanning Tree Protocol (STP):
Provides a single path
between end stations, avoiding and eliminating loops.
