Listening State - Cisco WS-C6506 Software Manual

Understanding How Spanning Tree Protocols Work
Figure 7-3
A port in the blocking state performs as follows:
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Listening State

The listening state is the first transitional state that a port enters after the blocking state. The port enters
this state when the spanning tree determines that the port should participate in frame forwarding.
Learning is disabled in the listening state.
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
7-8
Port 2 in Blocking State
Segment
frames
Port 1
Station
addresses
BPDUs
Filtering System
database module
BPDUs
Data
frames
Port 2
Blocking
Discards frames that are received from the attached segment.
Discards frames that are switched from another port for forwarding.
Does not incorporate station location into its address database. (There is no learning on a blocking
port, so there is no address database update.)
Receives BPDUs and directs them to the system module.
Does not transmit BPDUs that are received from the system module.
Receives and responds to network management messages.
Forwarding
Network
management
and data frames
Frame
forwarding
Network
management
frames
Segment
frames
Figure 7-4 shows a port in the listening state.
Chapter 7 Configuring Spanning Tree
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