Table 12. Relationship between IEEE 802.1D and IEEE 802.1w port states

IEEE 802.1D port

Admin. bridge

MAC operational

IEEE 802.1w port

Active topology port

state

port state

state

role

 

 

 

 

 

 

Listening

Enabled

True

Discarding

Included, root or

designated

 

 

 

 

 

 

 

 

 

Learning

Enabled

True

Learning

Included, root or

designated

 

 

 

 

 

 

 

 

 

Forwarding

Enabled

True

Forwarding

Included, root or

designated

 

 

 

 

 

 

 

 

 

Setting user-changeable STP parameters

The next table shows the default spanning-tree configuration.

Table 13. Default STP parameters

Feature

Default value

 

 

Enable state

STP enabled for all ports

 

 

Port priority

128

 

 

Port cost

auto

 

 

Bridge priority

32768

 

 

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

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Intel IXM5414E manual Setting user-changeable STP parameters, Forward Delay, 261, Feature Default value