Specifications

Rapid Spanning Tree Protocol
ExtremeWare XOS 11.0 Concepts Guide 217
2 Bridge E believes that bridge A is the root bridge. When bridge E receives the BPDU on its root port
from bridge F, bridge E:
• Determines that it received an inferior BPDU.
• Immediately begins the max age timer on its root port.
• Performs a configuration update.
As shown in Figure 26, after the configuration update, bridge E:
• Regards itself as the new root bridge.
• Sends BPDU messages on both of its designated ports to bridges F and D, respectively.
Figure 26: New root bridge selected
3 As shown in Figure 27, when bridge F receives the superior BPDU and configuration update from
bridge E, bridge F:
• Decides that the receiving port is the root port.
• Determines that bridge E is the root bridge.
Figure 27: Communicating new root bridge status to neighbors
EX_055c
B
A , 1
C
A , 2
E
E , 0
D
A , 3
BPDU
A
A , 0
F
F , 0
Designated
port
Root
port
EX_055d
B
A , 1
C
A , 2
E
E , 0
D
A , 3
A
A , 0
F
E , 1
Designated
port
Root
port