Cisco WS-C6506 Software Manual page 151

Chapter 7 Configuring Spanning Tree
Figure 7-4
addresses
database
A port in the listening state performs as follows:
• 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 at this point, so
•
there is no address database update.)
Receives BPDUs and directs them to the system module.
•
Processes BPDUs that are received from the system module.
•
Receives and responds to network management messages.
•
OL-8978-04
Port 2 in Listening State
All segment
Forwarding
frames
Port 1
Station
BPDUs
Filtering System
module
BPDUs
Data
frames
Port 2
Listening
BPDU and network
management frames
Network
management
and data frames
Frame
forwarding
Network
management
frames
All segment
frames
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
Understanding How Spanning Tree Protocols Work
7-9