The device layer of conventional distributed control system(DCS) in power plants adopts hardwired mode

so there is no talent problem in communication safety.With the open and transparent industrial control protocol communication network replacing the conventional DCS hardwire into the device layer

the protocol loopholes of industrial control communication protocol and the characteristics of being vulnerable to network attacks begin to highlight.This paper analyzes the loopholes and attacks of the communication network protocol in the device layer

focuses on the analysis of attack protection and gives an example of attack mode.At last

it points out that

on the protection of loopholes

management measures and technical measures should be adopted.It suggests to increase the time stamp and session mechanism when implementing industrial control protocols such as PROFIBUS and MODBUS

or to implement identity based authentication mechanism before establishing industrial protocol communication.