Forwarding State - IBM BladeCenter Installation And User Manual

The following illustration shows the actions that occur when a port is in the learning
state.

Forwarding state

A port in the forwarding state forwards packets. The port enters the forwarding state
from the learning state when the forward delay timer expires.
When the spanning-tree algorithm determines that a port should be changed to the
forwarding state, the following occurs:
The port is put into the listening state, where it receives bridge protocol data units
(BPDUs) and passes them to the switch CPU. BPDU packets from the CPU are
processed. If no BPDUs are received, this indicates that the port should go to the
blocking state:
v The port waits for the expiration of the forward delay timer. It then moves to the
v In the learning state, the port learns station location information from the source
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IBM BladeCenter 4-Port Gb Ethernet Switch Module: Installation and User's Guide
Addresses
Forwarding Forwarding
Database Database
Addresses
Discard
Data Data
Packets Packets
learning state.
address of packets and adds this information to its forwarding database.
Network Segment Network Segment
Port 1 Port 1
Forwarding
Network Network
Management Management
BPDUs
Packets Packets
CPU
BPDUs
Port 2 Port 2
Learning
Network Segment Network Segment
BPDUs
Data Data
Packets Packets
Switch Switch
Fabric Fabric