R3166-R3206-HP High-End Firewalls Network Management Configuration Guide-6PW101

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Figure 26 Network diagram for the STP algorithm
• Initial state of each device
The following table shows the initial state of each device.
Table 13 Initial state of each device
Device Port name
BPDU of
p
ort
Device A
AP1 {0, 0, 0, AP1}
AP2 {0, 0, 0, AP2}
Device B
BP1 {1, 0, 1, BP1}
BP2 {1, 0, 1, BP2}
Device C
CP1 {2, 0, 2, CP1}
CP2 {2, 0, 2, CP2}
• Comparison process and result on each device
The following table shows the comparison process and result on each device.
Table 14 Comparison process and result on each device
Device Comparison process
BPDU of port
after com
p
arison
Device A
• Port AP1 receives the configuration BPDU of Device B {1, 0, 1, BP1}.
Device A finds that the configuration BPDU of the local port {0, 0, 0,
AP1} is superior to the received configuration BPDU, and therefore
discards the received configuration BPDU.
• Port AP2 receives the configuration BPDU of Device C {2, 0, 2, CP1}.
Device A finds that the BPDU of the local port {0, 0, 0, AP2} is superior
to the received configuration BPDU, and therefore discards the received
configuration BPDU.
• Device A finds that both the root bridge and designated bridge in the
configuration BPDUs of all its ports are itself, so it assumes itself to be
the root bridge. In this case, it does not make any change to the
configuration BPDU of each port, and starts sending out configuration
BPDUs periodically.
AP1: {0, 0, 0, AP1}
AP2: {0, 0, 0, AP2}