Bull 1GB Intel Ethernet Switch Module, Installation And User Manual

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Understanding and Troubleshooting the Spanning Tree Protocol
263
Setting user-changeable STP parameters
The next table shows the default spanning-tree configuration.
The factory default settings are compatible with the majority of installations, and it is advisable to
keep the default settings as set at the factory unless it is absolutely necessary to change them. The
user-changeable parameters in the bridge are as follows:
Priority You can set a priority for the bridge from 0 to 65535. A value of 0 indicates 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 bridges that it
is indeed the root bridge. If you set a hello time for your bridge, and it is not the root
bridge, the set hello time will be used if and when your bridge 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, your bridge will start sending its
own BPDU to all other bridges for permission to become the root bridge. If your
bridge has the lowest bridge identifier, it will become the root bridge.
Forward Delay
The Forward Delay can be from 4 to 30 seconds. For IEEE 802.1D operation this is
the time that any port on the bridge spends in the learning state while moving from
Listening Enabled True Discarding
Included, root or
designated
Learning Enabled True Learning
Included, root or
designated
Forwarding Enabled True Forwarding
Included, root or
designated
Table 13. Default STP parameters
Feature Default value
Enable state STP enabled for all ports
Port priority 128
Port cost auto
Bridge priority 32768
Table 12. Relationship between IEEE 802.1D and IEEE 802.1w port states
IEEE 802.1D port
state
Admin. bridge
port state
MAC operational
IEEE 802.1w port
state
Active topology port
role