Brocade TurboIron 24X Series Configuration Guide - Manual (Page 584)

550 Brocade TurboIron 24X Series Configuration Guide
53-1003053-01
Configuring STP related features
For example, Port3/Switch 2 in Figure 83 , fails. Port4/Switch 3 becomes the new Root port.
Port4/Switch 3 sends an RST BPDU with a TCN to Port4/Switch 4. To propagate the topology
change, Port4/Switch 4 then starts a TCN timer on itself, on the bridge Root port, and on other
ports on that bridge with a Designated role. Then Port3/Switch 4 sends RST BPDU with the TCN to
Port4/Switch 2. (Note the new active Layer 2 path in
Figure 83 .)
FIGURE 83 Beginning of topology change notice
Switch 2 then starts the TCN timer on the Designated ports and sends RST BPDUs that contain the
TCN as follows (
Figure 84 ):
• Port5/Switch 2 sends the TCN to Port2/Switch 5
• Port4/Switch 2 sends the TCN to Port4/Switch 6
Bridge priority = 1000
Bridge priority = 200
Bridge priority = 60
Bridge priority = 900 Bridge priority = 400
Bridge priority = 300
Port2 Port2
Port2
Port2
Port3
Port3
Port3
Port3
Port3
Port3
Port4 Port4
Port4
Port4
Port5 Port 5
Port5
Port7 Port8
Indicates the active Layer 2 path
Indicates direction of TCN
Switch 1 Switch 2 Switch 5
Switch 3 Switch 4 Switch 6