Industrial Network Security Book Flashcards
modbus
Modbus is a serial communications protocol originally published by Modicon (now Schneider Electric) in 1979 for use with its programmable logic controllers (PLCs). Modbus has become a de facto standard communication protocol and is now a commonly available means of connecting industrial electronic devices. “Nonroutable”
RTU
A remote terminal unit (RTU) is a microprocessor-controlled electronic device that interfaces objects in the physical world to a distributed control system or SCADA system by transmitting telemetry data to a master system, and by using messages from the master supervisory system to control connected objects. “Nonroutable”
DNP3
DNP3 (Distributed Network Protocol) is a set of communications protocols used between components in process automation systems. Its main use is in utilities such as electric and water companies. Usage in other industries is not common. “Nonroutable”
Fieldbus
Fieldbus is the name of a family of industrial computer network protocols used for real-time distributed control, standardized as IEC 61158. A complex automated industrial system — such as manufacturing assembly line — usually needs a distributed control system—an organized hierarchy of controller systems—to function. “Nonroutable”
“Nonroutable” network
refers to those serial, bus, and point-to-point communication links that utilize Modbus/RTU etc. They interconnect devices and provide a communication path between digital devices, and in many cases are designed for remote command and control.
“Routable” network
Typically means a network utilizing TCP/IP. Also include routable variants of nonroutable protocols (e.g. Modbus over TCP/IP and DNP3 over TCP/UDP)
industrial switch
A switch that can withstand extreme conditions.
“enclave” and “zone”
Convenient for defining a closed group of assets, or a functional group of devices, services, and applications that make up a larger system. Communications are limited to only those devices, applications, and users that should be interacting with each other.
ESP
“Electronic Security Perimeter”. The boundary between secure and insecure zones.
Separation of assets
The separation of assets into functional groups allows specific services to be tightly locked down and controlled, and is one of the easiest methods of reducing the attack surface.
Allows you to configure the firewall more precisely.
Advanced Access Control
- Only allow a user to log in to an HMI if the user has successfully badged into the control room.
- Only allow a user to operate a given control from a specific controller.
- Only allow a use to authenticate during that user’s shift.
You can use two factor plus the above access control restrictions.
PLC
Programmable logic controller. A specialized industrial computer used to automate functions within manufacturing facilities. PLCs do not typically use commercially available OSs.
Ladder Logic
A set of connections between inputs (relay contacts) and outputs (relay coils). Every step is tested in each scan.
Relay
A relay is an electrically operated switch. Relays are used where it is necessary to control a circuit by a separate low-power signal, or where several circuits must be controlled by one signal.
Sequential Logic
Differs from ladder logic in that each step is executed in isolation and progresses to the next step only upon completion. Very common in batch operations.