An industrial control system and a method of inspecting one or more communication packets in an industrial control system may be provided, the industrial control system firewall module comprising a packet accessing component configured to access a communication packet of an industrial control system; a firewall rules database, the firewall rules database configured to store one or more firewall rules; an inspection module configured to access the one or more firewall rules based on an industrial protocol associated with the communication packet; and the inspection module is further configured to perform a comprehensive inspection of all header fields and data fields of the communication packet based on the one or more firewall rules accessed based on the industrial protocol associated with the communication packet.