H3C 交换机组网 mstp问题

Port21(GigabitEthernet1/0/21) received MSTP-dot1s Packet(Length: 102)

ProtocolVersionID: 03

BPDUType : 02

CIST Root ID : 61440.9c06-1b01-27f5

External RPC : 0  

Reg Root ID : 61440.9c06-1b01-27f5

Internal RPC : 0

CIST Bridge ID : 61440.9c06-1b01-27f5

CIST Port ID : 128.12

(Instance)Flags : (00)Desi[ FL ]  

*May 8 17:40:24:419 2021 XXXXXXX STP/7/FSMSTATE: Instance 0's port21(GigabitEthernet1/0/21) enters PPM%SENSING state. 

*May 8 17:40:24:419 2021 XXXXXXX STP/7/FSMSTATE: Instance 0's port21(GigabitEthernet1/0/21) enters PIM%CURRENT state.

 *May 8 17:40:24:419 2021 XXXXXXX STP/7/FSMSTATE: Instance 0's port21(GigabitEthernet1/0/21) enters PIM%RECEIVE state. 

*May 8 17:40:24:419 2021 XXXXXXX STP/7/FSMSTATE: Instance 0's port21(GigabitEthernet1/0/21) enters PIM%INFERIOR_DESIGNATED state. 

*May 8 17:40:24:419 2021 XXXXXXX STP/7/FSMSTATE: Instance 0's port21(GigabitEthernet1/0/21) enters PIM%CURRENT state. 

*May 8 17:40:24:523 2021 XXXXXXX STP/7/FSMSTATE: Instance 0's port21(GigabitEthernet1/0/21) enters PTX%PERIODIC state. 

*May 8 17:40:24:523 2021 XXXXXXX STP/7/FSMSTATE: Instance 0's port21(GigabitEthernet1/0/21) enters PTX%MSTP_DOT1S state. 

*May 8 17:40:24:524 2021 XXXXXXX STP/7/PKT: 

 Port21(GigabitEthernet1/0/21) sent MSTP-dot1s Packet(Length: 102) 

ProtocolVersionID: 03 

BPDUType : 02 

CIST Root ID : 32768.b0f9-632e-60b9 

External RPC : 20 

 Reg Root ID : 32768.b0f9-632e-8909 

Internal RPC : 0

 CIST Bridge ID : 32768.b0f9-632e-8909

 CIST Port ID : 128.21

 (Instance)Flags : (00)Desi[ P ] 

----[Port21(GigabitEthernet1/0/21)][DISCARDING]----

 Port protocol : Enabled

 Port role : Designated Port (Boundary)

 Port ID : 128.21

 Port cost(Legacy) : COnfig=auto, Active=200

 Desg.bridge/port : 32768.b0f9-632e-8909, 128.21

 Port edged : COnfig=disabled, Active=disabled

 Point-to-Point : COnfig=auto, Active=true

 Transmit limit : 10 packets/hello-time

 TC-Restriction : Disabled

 Role-Restriction : Disabled

 Protection type : NONE

 MST BPDU format : COnfig=auto, Active=802.1s

 Port Config-

 Digest-Snooping : Disabled

 Rapid transition : False

 Num of VLANs mapped : 1

 Port times : Hello 2s MaxAge 20s FwdDelay 15s MsgAge 1s RemHops 20

 BPDU sent : 229

          TCN: 0, Config: 0, RST: 0, MST: 229

 BPDU received : 229

          TCN: 0, Config: 0, RST: 0, MST: 229

俩交换机通过运营商专线直连

能帮分析下上面的信息，及产生的原因吗？