Overview Protocol Strucutre DNP3 SA Security Function Code Basic Authentication Object Update Key Change Objects Device Attributes Group 0 - Device Identification Wireshark dissector tree view & Hex dump Reference DNP3 (Distributed Network Protocol) is a vendor-neutral protocol used in SCADA and electric utility systems for communication between control centers (masters) and field devices (outstations). It typically runs over serial links or TCP/IP (commonly port 20000) and supports reading data, reporting events, and issuing control commands. DNP3 is designed for reliability in noisy environments and includes features like event-based reporting, time-stamping, and optional secure authentication for improved security and integrity.
reference
Function Code Name Descirption 0x20 Authentication Request Master -> Outstation 0x21 Autheitication Requestion - No Ack Master -> Outstation 0x83 Authenticaiton Response Outstation > Master
Group Var Hex Name Transmitted by 120 1 0x7801 Challenge Either 120 2 0x7802 Reply Either 120 3 0x7803 Aggressive Mode Request Either 120 4 0x7804 Session Key Status Request Master 120 5 0x7805 Session Key Status Outstation 120 6 0x7806 Session Key Change Master 120 7 0x7807 Error Either 120 9 0x7809 MAC Either
Group Var Hex Name Transmitted by 120 8 0x7808 User Certificate ** Master 120 10 0x780A User Status Change Master 120 11 0x780B Update Key Change Request Master 120 12 0x780C Update Key Change Reply Outstation 120 13 0x780D Update Key Change Master 120 14 0x780E Update Key Change Signature ** Master 120 15 0x780F Update Key Change Confirmation Either
Group Var Hex Name Transmitted by 0 250 0x00FA Device Product name & Model Outstation 0 252 0x00FC Manufacturers Name Outstation 0 242 0x00F2 Manufacturers Software Version Outstation 0 243 0x00F3 Manufacturers Serial Number Outstation 0 248 0x00F8 Manufacturers Hardware Version Outstation
Function Code: Authentication Request (0x20)
Distributed Network Protocol 3.0
Data Link Layer, Len: 14, From: 3, To: 4, DIR, PRM, Unconfirmed User Data
Start Bytes: 0x0564
Length: 14
Control: 0xc4 (DIR, PRM, Unconfirmed User Data)
Destination: 4
Source: 3
Data Link Header checksum: 0xd36d [correct]
[Data Link Header Checksum Status: Good]
Transport Control: 0xc0, Final, First(FIR, FIN, Sequence 0)
Data Chunks
[1 DNP 3.0 AL Fragment (8 bytes): #4(8)]
Application Layer: (FIR, FIN, Sequence 1, Authentication Request)
Application Control: 0xc1, First, Final(FIR, FIN, Sequence 1)
Function Code: Authentication Request (0x20)
Authentication Request Data Objects
Object(s): Authentication Session Key Status Request (Obj:120, Var:04) (0x7804), 1 point
Qualifier Field, Prefix: None, Range: 8-bit Single Field Quantity
Number of Items: 1
Point Number 0
User Number: 1
0000 05 64 0e c4 04 00 03 00 6d d3 c0 c1 20 78 04 07 .d......m... x..
0010 01 01 00 9e 40
DNP3 Specification Volumn 1 Wireshark DNP3 Dissector Youtube - DNP3 SA 3 Intermediate Siemens - DNP3 Specificiaton
