D-Link DES-3326 User Manual - page 57
DES-3326 Layer 3 Fast Ethernet Switch User’s Guide
Switch Management and Operating Concepts
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through to further ensure that a stable network topology is created
after a topology change.
Each port on a switch using STP exists is in one of the
following five states:
•
Blocking – the port is blocked from forwarding or receiving
packets
•
Listening – the port is waiting to receive BPDU packets
that may tell the port to go back to the blocking state
•
Learning – the port is adding addresses to its forwarding
database, but not yet forwarding packets
•
Forwarding – the port is forwarding packets
•
Disabled – the port only responds to network management
messages and must return to the blocking state first
A port transitions from one state to another as follows:
•
From initialization (switch boot) to blocking
•
From blocking to listening or to disabled
•
From listening to learning or to disabled
•
From learning to forwarding or to disabled
•
From forwarding to disabled
•
From disabled to blocking