Cisco WS-C6506 - Page 151

7-9
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 7 Configuring Spanning Tree
Understanding How Spanning Tree Protocols Work
Figure 7-4 Port 2 in Listening State
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.
Filtering
database
Frame
forwarding
System
module
Port 1
BPDUs
All segment
frames
BPDU and network
management frames
All segment
frames
Forwarding
Listening
Station
addresses
Network
management
and data frames
Port 2
S5693
Network
management
frames
Data
frames
BPDUs