H3C Technologies H3C S5560 Series Switches - Manual (Page 100)

66
Device Comparison process
Configuration BPDU on
ports after comparison
Device C
Port C1 performs the following tasks:
20. Receives the configuration BPDU of Port A2 {0, 0, 0, Port
A2}.
21. Determines that the received configuration BPDU is
superior to its existing configuration BPDU {2, 0, 2, Port
C1}.
22. Updates its configuration BPDU.
Port C2 performs the following tasks:
23. Receives the original configuration BPDU of Port B2 {1,
0, 1, Port B2}.
24. Determines that the received configuration BPDU is
superior to the existing configuration BPDU {2, 0, 2, Port
C2}.
25. Updates its configuration BPDU.
• Port C1: {0, 0, 0, Port
A2}
• Port C2: {1, 0, 1, Port
B2}
Device C performs the following tasks:
26. Compares the configuration BPDUs of all its ports.
27. Decides that the configuration BPDU of Port C1 is the
optimum.
28. 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}. Device C compares it with the existing
configuration BPDU of Port C2 {1, 0, 1, Port B2}. Device C
determines 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}
Port C2 performs the following tasks:
29. Receives the updated configuration BPDU of Port B2 {0,
5, 1, Port B2}.
30. Determines that the received configuration BPDU is
superior to its existing configuration BPDU {0, 10, 2, Port
C2}.
31. Updates its configuration BPDU.
Port C1 performs the following tasks:
32. Receives a periodic configuration BPDU {0, 0, 0, Port
A2} from Port A2.
33. Determines that it is the same as the existing
configuration BPDU.
34. Discards the received BPDU.
• Port C1: {0, 0, 0, Port
A2}
• Port C2: {0, 5, 1, Port
B2}