Forwarding State - Cisco WS-C6506 Software Manual

Chapter 7 Configuring Spanning Tree

Forwarding State

A port in the forwarding state forwards frames, as shown in
state from the learning state.
Figure 7-6
A port in the forwarding state performs as follows:
•
•
•
•
•
•
Use spanning-tree PortFast mode only on ports that are directly connected to individual workstations to
Caution
allow these ports to come up and go directly to the forwarding state, instead of having to go through the
entire spanning-tree initialization process. To prevent illegal topologies, enable spanning tree on ports
that are connected to switches or other devices that forward messages. For more information about
PortFast, see
Guard."
OL-8978-04
Port 2 in Forwarding State
All segment
frames
Port 1
Station
addresses
BPDUs
Filtering System
database module
BPDUs
Station
addresses
Port 2
Forwarding
Forwards frames that are received from the attached segment.
Forwards frames that are switched from another port for forwarding.
Incorporates station location information into its address database.
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.
Chapter 9, "Configuring Spanning-Tree PortFast, UplinkFast, BackboneFast, and Loop
Forwarding
Network
management
and data frames
Frame
forwarding
Network
management
and data frames
All segment
frames
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
Understanding How Spanning Tree Protocols Work
Figure 7-6. The port enters the forwarding
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