Huawei AR530 Series, Руководство по настройке

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Table 6-2 Description of the designated bridge and designated port
Object Designated Bridge Designated Port
Device A directly connected device
that forwards configuration
BPDUs to the local device The designated bridge's port that
forwards configuration BPDUs
to the local device
LAN A device that forwards
configuration BPDUs to the
local network segment The designated bridge's port that
forwards configuration BPDUs
to the local network segment.
As shown in Figure 6-3 , AP1 and AP2 are ports of S1; BP1 and BP2 are ports of S2; CP1
and CP2 are ports of S3.
– S1 sends configuration BPDUs to S2 through AP1, so S1 is the designated bridge for
S2, and AP1 is the designated port on S1.
– S2 and S3 are connected to the LAN. If S2 forwards configuration BPDUs to the LAN,
S2 is the designated bridge for the LAN, and BP2 is the designated port on S2.
Figure 6-3 Designated bridge and designated port
S1
S2 S3
AP1
AP2
BP1 CP1
BP2
CP2
LAN
After the root bridge, root ports, and designated ports are selected successfully, a tree topology
is set up on the entire network. When the topology is stable, only the root port and designated
ports forward traffic. The other ports are in the Blocking state; they only receive STP BPDUs
and do not forward user traffic.
Four Comparison Principles
During role election, STP devices compare four factors, which form a BPDU priority vector
{root ID, root path cost, sender BID, PID}.
Table 6-3 describes the port information carried in a configuration BPDU.
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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