Foundry Networks FESX User Manual

Foundry Configuration Guide for the FESX, FSX, and FWSX
7 - 40 © Foundry Networks, Inc. December 2005
After convergence is complete, Figure 7.19 shows the active Layer 2 path of the topology in Figure 7.18.
Figure 7.19 Active Layer 2 Path in Complex Topology
Propagation of Topology Change
The Topology Change state machine generates and propagates the topology change notification messages on
each port. When a Root port or a Designated port goes into a forwarding state, the Topology Change state
machine on those ports send a topology change notice (TCN) to all the bridges in the topology to propagate the
topology change.
NOTE: Edge ports, Alternate ports, or Backup ports do not need to propagate a topology change.
The TCN is sent in the RST BPDU that a port sends. Ports on other bridges in the topology then acknowledge the
topology change once they receive the RST BPDU, and send the TCN to other bridges until all the bridges are
informed of the topology change.
Port2 Port2
Port7 Port8
Port3
Port3
Port4Port4
Port2
Port3
Bridge priority = 200
Bridge priority = 400
Bridge priority = 300
Bridge priority = 1000
Port4
Port5
Port3
Bridge priority = 900
Bridge priority = 60
Port2
Port5 Port5
Port4
Indicates the active Layer 2 path
Switch 1
Switch 2
Switch 5
Switch 6
Switch 4
Switch 3

Foundry Networks FESX Specifications

General

Brand	Foundry Networks
Model	FESX
Category	Switch
Language	English