Extreme Networks ExtremeWare XOS Guide Manual page 317

5 Upon receiving the proposal, bridge E (as shown in
Performs a configuration update.
●
Changes its receiving port to a root port.
●
The existing designated port enters the blocking state.
Bridge E then sends:
A "propose" message to bridge F.
●
An "agree" message from its root port to bridge D.
●
Figure 39: Communicating port status to neighbors
A
A , 0
F
E , 1
6 To complete the topology change (as shown in
Bridge D moves the port that received the "agree" message into the forwarding state.
●
Bridge F confirms that its receiving port (the port that received the "propose" message) is the root
●
port, and immediately replies with an "agree" message to bridge E to unblock the proposing port.
Figure 40: Completing the topology change
A
A , 0
F
A , 5
Figure 41 displays the new topology.
ExtremeWare XOS 11.1 Concepts Guide
B
A , 1
Designated
port
E
A , 4
Agree BPDU
B
A , 1
Root
port
E
A , 4
Figure 39):
C
A , 2
Root
port
D
A , 3
Figure 40):
C
A , 2
Designated
port
D
A , 3
Rapid Spanning Tree Protocol
EX_055f
EX_055g
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