。
From listening to learning or to disabled
。
From learning to forwarding or to disabled
。
From forwarding to disabled
。
From disabled to blocking
Switch
Blocking
Listening
Learning
Forwarding
Disable
STP Port State Transitions
You can modify each port state by using management software. When you enable STP, every port on
every switch in the network goes through the blocking state and then transitions through the states of
listening and learning at power up. If properly configured, each port stabilizes to the forwarding or
blocking state. No packets (except BPDUs) are forwarded from, or received by, STP enabled ports until
the forwarding state is enabled for that port.
2. STP Parameters
STP Operation Levels
The Switch allows for two levels of operation: the switch level and the port level. The switch level forms a
spanning tree consisting of links between one or more switches. The port level constructs a spanning
tree consisting of groups of one or more ports. The STP operates in much the same way for both levels.
NOTICE:
On the switch level, STP calculates the Bridge Identifier for each switch and then sets the
Root Bridge and the Designated Bridges.
On the port level, STP sets the Root Port and the Designated Ports.
The following are the user-configurable STP parameters for the switch level:
Parameter
Description
Default Value
Bridge Identifier(Not user
A combination of the User-set priority and
32768 + MAC
