16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series
Feature Overview
19
Cisco IOS Release 12.2(2)XT, 12.2(8)T, and 12.2(15)ZJ
Forwarding State
A Layer 2 interface in the forwarding state forwards frames, as shown in
Figure 8
. The Layer 2 interface
enters the forwarding state from the learning state.
Figure 8
Interface 2 in Forwarding State
A Layer 2 interface in the forwarding state performs as follows:
•
Forwards frames received from the attached segment.
•
Forwards frames switched from another Layer 2 interface for forwarding.
•
Incorporates end station location information into its address database.
•
Receives BPDUs and directs them to the system module.
•
Processes BPDUs received from the system module.
•
Receives and responds to network management messages.
Filtering
database
Frame
forwarding
System
module
Port 1
BPDUs
All segment
frames
All segment
frames
Forwarding
Forwarding
BPDUs
Station
addresses
Network
management
and data frames
Port 2
S5695
Network
management
and data frames
Station
addresses