Operation Manual – MSTPH3C S3610&S5510 Series Ethernet Switches Chapter 1 MSTP Configuration1-7Table 1-4 Initial state of each deviceDevice Port name BPDU of portAP1 {0, 0, 0, AP1}Device AAP2 {0, 0, 0, AP2}BP1 {1, 0, 1, BP1}Device BBP2 {1, 0, 1, BP2}CP1 {2, 0, 2, CP1}Device CCP2 {2, 0, 2, CP2}z Comparison process and result on each deviceThe following table shows the comparison process and result on each device.Table 1-5 Comparison process and result on each deviceDevice Comparison processBPDU ofport aftercomparisonDeviceAz Port AP1 receives the configuration BPDU of DeviceB {1, 0, 1, BP1}. Device A finds that the configurationBPDU of the local port {0, 0, 0, AP1} is superior to theconfiguration received message, and discards thereceived configuration BPDU.z Port AP2 receives the configuration BPDU of DeviceC {2, 0, 2, CP1}. Device A finds that the BPDU of thelocal port {0, 0, 0, AP2} is superior to the receivedconfiguration BPDU, and discards the receivedconfiguration BPDU.z Device A finds that both the root bridge anddesignated bridge in the configuration BPDUs of all itsports are Device A itself, so it assumes itself to be theroot bridge. In this case, it does not make any changeto the configuration BPDU of each port, and startssending out configuration BPDUs periodically.AP1: {0, 0, 0,AP1}AP2: {0, 0, 0,AP2}
