
Operation Manual - STP
Quidway S3500 Series Ethernet Switches
Chapter 1 MSTP Region-configuration
Huawei Technologies Proprietary
1-5
Switch A
Switch C
Switch B
CP2
BP2
CP1
BP1
AP2
AP1
LAN
Figure 1-3
Designated switch and designated port
For a switch, the designated switch is a switch in charge of forwarding packets to the
local switch via a port called the designated port accordingly. For a LAN, the designated
switch is a switch that in charge of forwarding packets to the network segment via a port
called the designated port accordingly. As illustrated in the Figure 1-3, Switch A
forwards data to Switch B via the port AP1. So to Switch B, the designated switch is
Switch A and the designated port is AP1. Also in the figure above, Switch B and Switch
C are connected to the LAN and Switch B forwards packets to LAN. So the designated
switch of LAN is Switch B and the designated port is BP2.
Note:
AP1, AP2, BP1, BP2, CP1 and CP2 respectively delegate the ports of Switch A, Switch
B and Switch C.
z
The specific calculation process of STP algorithm.
The following example illustrates the calculation process of STP.
The Figure 1-4 below illustrates the network.
Switch A
with priority 0
Switch C
with priority 2
Switch B
with priority 1
CP2
BP2
CP1
BP1
AP2
AP1
4
10
5
Figure 1-4
Ethernet switch networking