Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 291)

currently being received by the current Root port (Port4). Therefore, Port3 retains the role of Alternate
port.
Ports 3/Switch 1 and Port5/Switch 1 are physically connected. Port5/Switch 1 received RST BPDUs that
are superior to those received on Port3/Switch 1; therefore, Port5/Switch 1 is given the Backup port role
while Port3 is given the Designated port role. Port3/Switch 1, does not go directly into a forwarding
state. It waits until the forward delay time expires twice on that port before it can proceed to the
forwarding state.
Once convergence is achieved, the active Layer 2 forwarding path converges as shown in the following
figure.
FIGURE 55 Active Layer 2 path
Convergence after a link failure
The following figure illustrates a link failure in the 802.1W topology. In this example, Port2/Switch, which
is the port that connects Switch 2 to the root bridge (Switch 1), failed and both Switch 2 and Switch 1
are affected by the topology change.
Convergence after a link failure
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