Huawei AR530 series Configuration Manual page 190

Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
2.
Issue 01 (2014-11-30)
Table 6-10 Initial state of each device
Device Port
DeviceA Port A1
Port A2
DeviceB Port B1
Port B2
DeviceC Port C1
Port C2
Configuration comparison and result
Table 6-11 describes configuration comparison process and result.
NOTE
The fields in a configuration BPDU are {root ID, root path cost, sender BID, PID}.
Table 6-11 Topology calculation process and result
Dev Comparison
ice
Devi l Port A1 receives the configuration BPDU {1,
ceA
0, 1, Port B1} from Port B1 and finds it inferior
to its own configuration BPDU {0, 0, 0, Port
A1}, so Port A1 discards the received
configuration BPDU.
l Port A2 receives the configuration BPDU {2,
0, 2, Port C1} from Port C1 and finds it inferior
to its own configuration BPDU {0, 0, 0, Port
A2} superior, so Port A2 discards the received
configuration BPDU.
l DeviceA finds that the root bridge and
designated bridge specified in the
configuration BPDUs on its ports are both
itself. Therefore, DeviceA considers itself as
the root bridge and periodically sends
configuration BPDUs from each port without
modifying the BPDUs.
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Configuration BPDU
{0, 0, 0, Port A1}
{0, 0, 0, Port A2}
{1, 0, 1, Port B1}
{1, 0, 1, Port B2}
{2, 0, 2, Port C1}
{2, 0, 2, Port C2}
6 STP/RSTP Configuration
Configuration BPDU
After Comparison
l Port A1: {0, 0, 0, Port
A1}
l Port A2: {0, 0, 0, Port
A2}
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