This indicates a possible attempt by an attacker to shut down an application on a DNP3 server by spoofing the IP address of an authorized DNP3 client.
The Distributed Network Protocol (DNP3) is an industry standard for inter-operations between devices and is commonly found in SCADA systems. DNP3 enables data and command exchange between a server and a client device. The server sends commands and controls the operation of a client device.
Denial of Service
Investigate the source of the traffic to prevent further attacks.