H3C S5830V2 series, Configuration Manual

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In Table 6 , each configuration BPDU contains the following fields: root bridge ID, root path cost,
designated bridge ID, and designated port ID.
Table 6 Initial state of each device
Device Port name
Configuration BPDU on the
port
Device A
Port A1 {0, 0, 0, Port A1}
Port A2 {0, 0, 0, Port A2}
Device B
Port B1 {1, 0, 1, Port B1}
Port B2 {1, 0, 1, Port B2}
Device C
Port C1 {2, 0, 2, Port C1}
Port C2 {2, 0, 2, Port C2}
2. Configuration BPDUs comparison on each device.
In
Table 7 , each configuration BPDU contains the following fields: root bridge ID, root path cost,
designated bridge ID, and designated port ID.
Table 7 Comparison process and result on each device
Device Comparison process
Configuration BPDU on
ports after comparison
Device A
Port A1 performs the following actions:
1. Receives the configuration BPDU of Port B1 {1, 0, 1, Port
B1}.
2. Determines that its existing configuration BPDU {0, 0, 0,
Port A1} is superior to the received configuration BPDU.
3. Discards the received one.
Port A2 performs the following actions:
1. Receives the configuration BPDU of Port C1 {2, 0, 2, Port
C1}.
2. Determines that its existing configuration BPDU {0, 0, 0,
Port A2} is superior to the received configuration BPDU.
3. Discards the received one.
Device A determines that it is both the root bridge and
designated bridge in the configuration BPDUs of all its ports.
It considers itself as the root bridge. It does not change the
configuration BPDU of any port and starts to periodically
send configuration BPDUs.
•
Port A1: {0, 0, 0, Port
A1}
•
Port A2: {0, 0, 0, Port
A2}