User's Manual

181

Figure 174 STP network

As shown in Figure 174, the priority values of Device A, Device B, and Device C are 0, 1, and 2, and the

path costs of links among the three devices are 5, 10, and 4, respectively.

1. Device state initialization.

In Table 55, each configura

tion BPDU contains the following fields: root bridge ID, root path cost,

designated bridge ID, and designated port ID.

Table 55 Initial state of each device

Device Port name BPDU of

ort

Device A

AP1 {0, 0, 0, AP1}

AP2 {0, 0, 0, AP2}

Device B

BP1 {1, 0, 1, BP1}

BP2 {1, 0, 1, BP2}

Device C

CP1 {2, 0, 2, CP1}

CP2 {2, 0, 2, CP2}

2. Configuration BPDUs comparison on each device.

In Table 56, each configura

tion BPDU contains the following fields: root bridge ID, root path cost,

designated bridge ID, and designated port ID.