Huawei AR530 Series, Руководство по настройке

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Dev
ice Comparison Configuration BPDU
After Comparison
l
DeviceC compares the configuration BPDU on
each port and finds that the configuration
BPDU on Port C1 is optimal. DeviceC selects
Port C1 as the root port and retains the
configuration BPDU on Port C1.
l DeviceC calculates the configuration BPDU
{0, 10, 2, Port C2} for Port C2 based on the
configuration BPDU and path cost of the root
port, and compares the calculated
configuration BPDU with the original
configuration BPDU {1, 0, 1, Port B2} on Port
C2. The calculated configuration BPDU is
superior to the original one, so DeviceC selects
Port C2 as the designated port and replaces its
configuration BPDU with the calculated one.
l
Root port (Port C1): {0,
0, 0, Port A2}
l Designated port (Port
C2): {0, 10, 2, Port C2}
l Port C2 receives the configuration BPDU {0,
5, 1, Port B2} from Port B2 and finds it superior
to its own configuration BPDU {0, 10, 2, Port
C2}, so Port C2 updates its configuration
BPDU.
l Port C1 receives the configuration BPDU {0,
0, 0, Port A2} from Port A2 and finds it the
same as its own configuration BPDU, so Port
C1 discards the received configuration BPDU.
l Port C1: {0, 0, 0, Port
A2}
l
Port C2: {0, 5, 1, Port
B2}
l The root path cost of Port C1 is 10 (root path
cost 0 in the received configuration BPDU plus
the link patch cost 10), and the root path cost
of Port C2 is 9 (root path cost 5 in the received
configuration BPDU plus the link patch cost 4).
DeviceC finds that Port C2 has a smaller root
path cost and therefore considers the
configuration BPDU of Port C2 superior to that
of Port C1. DeviceC then selects Port C2 as the
root port and retains its configuration BPDU.
l DeviceC calculates the configuration BPDU
{0, 9, 2, Port C1} for Port C1 based on the
configuration BPDU and path cost of the root
port, and finds the calculated configuration
BPDU inferior to the original configuration
BPDU {0, 0, 0, Port A2} on Port C2. DeviceC
blocks Port C1 and does not update its
configuration BPDU. Port C1 no longer
forwards data until STP recalculation is
triggered, for example, when the link between
DeviceB and DeviceC is Down.
l Blocked port (Port C1):
{0, 0, 0, Port A2}
l Root port (Port C2): {0,
5, 1, Port B2}
Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
6 STP/RSTP Configuration
Issue 01 (2014-11-30) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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