Dell PowerConnect B-RX BigIron RX Series Configuration Guide v02.7.02 - Page 443

Convergence in a complex RSTP topology 13 After convergence is complete, Figure 58 shows the active Layer 2 path of the topology in Figure 57. FIGURE 58 Active Layer 2 path in complex topology Switch 2 Bridge priority = 200 Switch 1 Bridge priority = 1000 Port2 Port7 Port2 Port8 Port5 Port2 Switch 5 Bridge priority = 60 Port3 Port3 Port4 Port3 Port2 Port3 Port4 Switch 3 Bridge priority = 300 Port4 Port3 Port5 Switch 4 Bridge priority = 400 Port4 Port5 Port3 Switch 6 Bridge priority = 900 Indicates the active Layer 2 path 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. BigIron RX Series Configuration Guide 371 53-1001810-01