H3C Technologies H3C WX3000E Series Wireless Switches User Manual
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Table 11 Comparison process and result on each device
Device
Comparison process
Configuration BPDU
on ports after
comparison
Device A
•
Port A1 receives the configuration BPDU of Port B1 {1, 0, 1, Port B1},
finds that its existing configuration BPDU {0, 0, 0, Port A1} is superior
to the received configuration BPDU, and discards the received one.
•
Port A2 receives the configuration BPDU of Port C1 {2, 0, 2, Port C1},
finds that its existing configuration BPDU {0, 0, 0, Port A2} is superior
to the received configuration BPDU, and discards the received one.
•
Device A finds that it is both the root bridge and designated bridge in
the configuration BPDUs of all its ports, and considers itself as the root
bridge. It does not change the configuration BPDU of any port and
starts to periodically send out configuration BPDUs.
•
Port A1: {0, 0, 0,
Port A1}
•
Port A2: {0, 0, 0,
Port A2}
Device B
•
Port B1 receives the configuration BPDU of Port A1 {0, 0, 0, Port A1},
finds that the received configuration BPDU is superior to its existing
configuration BPDU {1, 0, 1, Port B1}, and updates its configuration
BPDU.
•
Port B2 receives the configuration BPDU of Port C2 {2, 0, 2, Port C2},
finds that its existing configuration BPDU {1, 0, 1, Port B2} is superior
to the received configuration BPDU, and discards the received one.
•
Port B1: {0, 0, 0,
Port A1}
•
Port B2: {1, 0, 1,
Port B2}
•
Device B compares the configuration BPDUs of all its ports, decides
that the configuration BPDU of Port B1 is the optimum, and selects Port
B1 as the root port with the configuration BPDU unchanged.
•
Based on the configuration BPDU and path cost of the root port,
Device B calculates a designated port configuration BPDU for Port B2
{0, 5, 1, Port B2}, and compares it with the existing configuration
BPDU of Port B2 {1, 0, 1, Port B2}. Device B finds that the calculated
one is superior, decides that Port B2 is the designated port, replaces
the configuration BPDU on Port B2 with the calculated one, and
periodically sends out the calculated configuration BPDU.
•
Root port (Port B1):
{0, 0, 0, Port A1}
•
Designated port
(Port B2): {0, 5, 1,
Port B2}
Device C
•
Port C1 receives the configuration BPDU of Port A2 {0, 0, 0, Port A2},
finds that the received configuration BPDU is superior to its existing
configuration BPDU {2, 0, 2, Port C1}, and updates its configuration
BPDU.
•
Port C2 receives the original configuration BPDU of Port B2 {1, 0, 1,
Port B2}, finds that the received configuration BPDU is superior to the
existing configuration BPDU {2, 0, 2, Port C2}, and updates its
configuration BPDU.
•
Port C1: {0, 0, 0,
Port A2}
•
Port C2: {1, 0, 1,
Port B2}
•
Device C compares the configuration BPDUs of all its ports, decides
that the configuration BPDU of Port C1 is the optimum, and selects
Port C1 as the root port with the configuration BPDU unchanged.
•
Based on the configuration BPDU and path cost of the root port,
Device C calculates the configuration BPDU of Port C2 {0, 10, 2, Port
C2}, and compares it with the existing configuration BPDU of Port C2
{1, 0, 1, Port B2}. Device C finds that the calculated configuration
BPDU is superior to the existing one, selects Port C2 as the designated
port, and replaces the configuration BPDU of Port C2 with the
calculated one.
•
Root port (Port
C1): {0, 0, 0, Port
A2}
•
Designated port
(Port C2): {0, 10,
2, Port C2}