Free ISA-IEC-62443 braindumps download (ISA-IEC-62443 exam dumps Free Updated Feb 26, 2026) [Q56-Q73]

ISA/IEC 62443-3-2 is titled “Security risk assessment for system design” and provides a methodology for performing cybersecurity risk assessments and for the design of security zones and conduits within IACS. It describes how to identify assets, assess threats and vulnerabilities, assign Security Levels (SLs), and develop a security design based on risk.
Reference: ISA/IEC 62443-3-2:2020, Scope and Section 4.1 (“Purpose and objectives of 62443-3-2”).

ISA/IEC 62443-3-2 specifically provides methodology and guidance for performing risk assessments and defining zones and conduits based on those assessments.
“This standard describes a process for conducting a cybersecurity risk assessment and defines the concept of zones and conduits for segmenting IACS. It provides guidance for assigning security levels and designing mitigation strategies accordingly.”
– ISA/IEC 62443-3-2:2020, Clause 5.3 – Zones and Conduits
It is the key reference for system integrators during design and architecture phases of IACS security.
References:
ISA/IEC 62443-3-2:2020 – Clauses 5.2 and 5.3
ISA/IEC 62443-1-1 – Introduction to zones, conduits, and SL-T

The ISA/IEC 62443 series organizes documents into categories: General, Policies and Procedures, System, and Component. The document titled “Patch management in the IACS environment” is part of the Policies and Procedures group (specifically, ISA/IEC 62443-2-3). This group addresses processes, procedures, and organizational measures for cybersecurity in industrial automation and control systems (IACS), including topics like patch management, which deals with evaluating, testing, and installing updates or patches to reduce vulnerabilities in control systems.
Reference: ISA/IEC 62443-2-3:2015, Introduction and Scope; ISA/IEC 62443-1-1:2007, Section 4.1.2.

The Modbus Application Protocol is a messaging protocol that provides client/server communication between devices connected on different types of buses or networks. It is positioned at level 7 of the OSI model, which is the application layer. The application layer is the highest level of the OSI model and defines the rules and formats for data exchange between applications. The Modbus Application Protocol is independent of the underlying communication layers and can be implemented using different transport protocols, such as TCP/IP, serial, or Modbus Plus. The Modbus Application Protocoldefines the function codes, data formats, and error codes for Modbus transactions123 References:
* MODBUS APPLICATION PROTOCOL SPECIFICATION V1
* Modbus – Wikipedia
* Overview of Modbus – EPICS support for Modbus – GitHub Pages

Datagram Transport Layer Security (DTLS) and Secure Sockets Layer (SSL) are both commonly used protocols for managing secure data transmission on the Internet. DTLS is a variant of SSL that is designed to work over datagram protocols such as UDP, which are used for real-time applications such as voice and video. SSL is a protocol that provides encryption, authentication, and integrity for data transmitted over TCP, which is used for reliable and ordered delivery of data. Both DTLS and SSL use certificates and asymmetric cryptography to establish a secure session between the communicating parties, and then use symmetric cryptography to encrypt the data exchanged. DTLS and SSL are widely used in web browsers, email clients, VPNs, and other applications that require secure communication over the Internet. References:
* ISA/IEC 62443 Standards to Secure Your Industrial Control System, Module 3: Introduction to Cryptography, pages 3-5 to 3-7
* Using the ISA/IEC 62443 Standards to Secure Your Control System, Chapter 6: Securing Communications, pages 125-126

At layer 4 of the OSI model, also known as the transport layer, the application that will handle a packet inside a host is identified by a TCP/UDP port number. A port number is a 16-bit integer that is assigned to a specific application or service that runs on a host. Port numbers are used to multiplex and demultiplex the data streams that are exchanged between hosts and end systems. Multiplexing is the process of combining multiple data streams into one, while demultiplexing is the process of separating one data stream into multiple ones. Port numbers are part of the header of the transport layer protocol data unit (PDU), which is called a segment for TCP and a datagram for UDP. The header contains the source port number and the destination port number, which indicate the applications that are involved in the communication. For example, if a host sends a packet to another host using the HTTP protocol, which runs on port 80 by default, the source port number would be a random number chosen by the sender, and the destination port number would be 80. The receiver would then use the destination port number to demultiplex the packet and deliver it to the HTTP application.
Port numbers are divided into three ranges: well-known ports (0-1023), registered ports (1024-49151), and dynamic or private ports (49152-65535). Well-known ports are reserved for common and standardized applications and services, such as HTTP (80), FTP (21), and SSH (22). Registered ports are assigned by the Internet Assigned Numbers Authority (IANA) to specific applications and services that request them, such as Skype (49175) and Minecraft (25565). Dynamic or private ports are not assigned by any authority and can be used by any application or service that needs them, such as ephemeral ports that are used for temporary connections.
The other options are not valid identifiers for the application that will handle a packet inside a host at layer 4 of the OSI model. A TCP/UDP application ID is not a term that is used in the OSI model or the TCP/IP model.
A TCP/UDP host ID is not a term that is used in the OSI model or the TCP/IP model, and it would be more appropriate for layer 3, which is the network layer, where the host is identified by an IP address. A TCP/UDP registry number is not a term that is used in the OSI model or the TCP/IP model, and it would be more appropriate for layer 5, which is the session layer, where the registry number is used to identify a session between two hosts.
References:
* Transport Layer | Layer 4 | The OSI-Model1
* OSI model – Wikipedia2
* What is Layer 4 of the OSI Model? | Glossary | A10 Networks3
* What Are the 7 Layers of the OSI Model? | Webopedia4

ISA/IEC 62443 highlights that many IACS environments operate with long lifecycles and strict availability requirements, which often results in delayed or infrequent patching.
Step 1: Legacy systems and uptime constraints
IACS components may run for decades without replacement. Applying patches can introduce operational and safety risks, so updates are often postponed.
Step 2: Accumulated vulnerabilities
Unpatched systems accumulate known vulnerabilities that attackers can exploit using publicly available tools.
Step 3: Why other options are incorrect
IACS systems are no longer isolated. They do require patches, and they rarely run the latest updates.
Therefore, unpatched software is a major vulnerability factor.

Transport Layer Security (TLS) is the standard protocol for securing web communications, including HTTP over TLS (HTTPS) in web browsers. TLS provides encryption, authentication, and data integrity, and has replaced SSL as the primary means of securing browser-based communications.
Reference: ISA/IEC 62443-3-3:2013, Section 4.2.3.7 (“Use of TLS for secure communication”); NIST SP
800-52 Rev. 2.

ISA/IEC 62443-2-5 provides requirements and guidance specifically for service providers (such as those delivering IACS-related managed services, maintenance, or cybersecurity services). While system integrators and asset owners use this guidance, its main audience is service providers, ensuring that their procedures align with cybersecurity best practices for IACS.
Reference: ISA/IEC 62443-2-5:2019, Scope and Introduction.

SP Element 1 – Organizational Security Measures focuses on policies, roles, and governance at the organizational level. It includes:
Background checks
Security awareness training
Supply chain security governance
However, malware protection is not considered part of SP Element 1, as it falls under technical or system integrity controls, typically found in SP Element 4 (System Integrity).
“SP Element 1 includes activities such as assigning roles and responsibilities, background checks, training, and supply chain oversight – not technical malware defenses.”
– ISA/IEC 62443-2-1:2010, Clause 4.3.4 – Table 2 (SP Elements Overview) References:
ISA/IEC 62443-2-1 – Clause 4.3.4
SP Element 4 – Where malware protection is categorized

ISA/IEC 62443-2-1 requires objective, verifiable evidence of cybersecurity controls during audits and assessments.
Step 1: Evidence-based verification
Auditors assess whether required processes and technical controls are implemented and effective.
Documentation such as configurations, procedures, logs, and policies provides verifiable proof.
Step 2: Why documentation matters
Written records demonstrate consistency, repeatability, and governance-key goals of the standard.
Step 3: Why other options fail
Financial spending does not prove control effectiveness. Anecdotes are subjective. Marketing materials are not evidence.
Thus, documentation verifying use and configuration of technologies is the correct evidence.

An intrusion detection system (IDS) is a network security tool that monitors network traffic and devices for known malicious activity, suspicious activity or security policy violations. The IDS sends alerts to IT and security teams when it detects any security risks and threats. However, an IDS does not block or prevent the malicious activity, it only detects and reports it. Therefore, an IDS is not the lock on the door for networks and computer systems, nor is it effective against all vulnerabilities in networks and computer systems. An IDS can be combined with an intrusion prevention system (IPS) to block the malicious activity in real time. References:
What is Intrusion Detection Systems (IDS)? How does it Work? | Fortinet1 Intrusion Detection System (IDS) – GeeksforGeeks2 What is an intrusion detection system (IDS)? – IBM3

The Open Systems Interconnection (OSI) model is a framework that describes the functions of a networking system. The OSI model categorizes the computing functions of the different network components, outlining the rules and requirement needed to support the interoperability of the software and hardware that make up the network1.
The OSI model consists of seven abstraction layers arranged in a top-down order: Physical, Data Link, Network, Transport, Session, Presentation, and Application. The Transport layer is the fourth layer in the OSI model, and it is responsible for ensuring reliable and efficient data transfer between the Network layer and the Session layer2. The Transport layer uses protocols such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) to provide end-to-end communication services, such as error detection and correction, flow control, congestion control, and segmentation2.
The image that you sent shows a 3D representation of the OSI model, with the layers stacked on top of each other. The missing layer is the Transport layer, which isrepresented by a pink box with a white arrow pointing to it. The arrow is labeled “TCP, UDP”.
1: What is the OSI Model? 7 Network Layers Explained | Fortinet 2: What is OSI Model | 7 Layers Explained
– GeeksforGeeks