IEC 62442-4-2 Hardening Guide for MX-NOS & MX-ROS

Technical Guide

IEC 62443-4-2 Hardening Checklist for MX-NOS & MX-ROS

This guide summarises nine key hardening actions for Moxa MX-NOS and MX-ROS devices to help support IEC 62443-4-2 Security Level 2 alignment.

In industrial networks, switches, routers and other infrastructure devices play a critical role in maintaining secure and reliable communication between systems. If these devices are left with default settings, unnecessary services or weak access controls, they can introduce avoidable security risks into the wider network.

Reduce Risk

Replace default access settings, restrict management access and limit unnecessary services.

Strengthen Access

Use stronger passwords, account lockout, automatic logout and trusted access controls.

Improve Visibility

Send events, faults and security logs to approved monitoring or logging systems.

What This Hardening Checklist Covers

The actions below are designed to reduce unauthorised access, strengthen authentication, improve monitoring, limit insecure services and protect exported configuration data.

Access control

Replace default credentials, restrict management access and ensure inactive sessions are closed automatically.

Authentication protection

Apply password complexity rules and login failure lockout policies to help reduce the risk of brute-force or guessing attacks.

Monitoring and resilience

Send logs to monitoring systems, disable unnecessary services and protect exported backups with configuration file encryption.

Practical security baseline

These steps should be applied during commissioning and reviewed regularly to help maintain secure operation and continued alignment with IEC 62443-4-2 expectations.

Nine Key Hardening Actions

Use this checklist as a practical starting point when provisioning, reviewing or maintaining MX-NOS and MX-ROS devices in industrial network environments.

Change Default Credentials & SNMP Community Strings

Default administrator credentials and SNMP community strings are widely known and should be replaced during device provisioning to prevent easy unauthorised access.

Path

Password: System > Account Management > User Accounts
SNMP: System > Management Interface > SNMP

Action

Create a new administrator account with a strong password, remove or rename the default account, replace default SNMP community strings, and use SNMPv3 where possible.

Configure SNMP Traps or a Syslog Server

Sending event, fault and security logs to a separate monitoring server improves visibility and helps ensure suspicious activity is detected and investigated.

Path

SNMP Trap: Diagnostics > Event Logs and Notifications > SNMP Trap/Inform
Syslog: Diagnostics > Event Logs and Notifications > Syslog

Action

Configure the device to send SNMP traps and/or Syslog messages to an approved central monitoring or logging server.

Enable Trusted Access

Trusted access restricts device management access to approved IP addresses or subnets, reducing the chance of unauthorised systems reaching the management interface.

Path

Security > Device Security > Trusted Access

Action

Define the permitted management hosts or subnets and block access from all other network addresses.

Enable Automatic Logout

Automatic logout closes inactive management sessions, reducing the risk of unattended or forgotten sessions being used by unauthorised users.

Path

Security > Device Security > Login Policy

Action

Keep auto logout enabled and set an appropriate inactivity timeout; do not set the timeout value to 0.

Enforce Password Strength & Complexity

Password complexity rules help protect the device against weak passwords and reduce the effectiveness of brute-force and guessing attacks.

Path

System > Account Management > Password Policy

Action

Enforce strong password requirements, including a minimum length of 12 characters with uppercase, lowercase, numeric and special characters.

Enable Login Failure Lockout

Login failure lockout limits repeated authentication attempts and helps prevent attackers from making unlimited password guesses.

Path

Security > Device Security > Login Policy

Action

Configure a lockout policy, such as locking access after three failed login attempts for a defined period, and ensure the device time is correct.

Disable Unused & Insecure Services

Unused ports and insecure management services increase the device attack surface and should be disabled unless they are required for operation.

Path

Physical ports: Network Configuration > Ports > Port Settings
Management interfaces: System > Management Interface > User Interface

Action

Disable unused ports and turn off insecure management interfaces such as HTTP and Telnet, using secure alternatives such as HTTPS and SSH where available.

Set a Login Banner Message

A login message informs users that the device is protected, identifies authorised use requirements and provides a clear warning before access.

Path

Security > Device Security > Login Policy

Action

Configure a login banner stating system ownership, authorised-use conditions and that unauthorised access is prohibited.

Enable Configuration File Encryption

Encrypting exported configuration files helps protect sensitive device settings and credentials if a backup file is lost, copied or stolen.

Path

System > System Management > Configuration Backup and Restore

Action

Enable configuration file encryption and protect exported backups with a strong encryption password.

Quick Settings Map

This section summarises where the main hardening settings can typically be found within the MX-NOS or MX-ROS interface.

User accounts
System > Account Management > User Accounts
SNMP
System > Management Interface > SNMP
SNMP traps
Diagnostics > Event Logs and Notifications > SNMP Trap/Inform
Syslog
Diagnostics > Event Logs and Notifications > Syslog
Trusted access
Security > Device Security > Trusted Access
Login policy
Security > Device Security > Login Policy
Password policy
System > Account Management > Password Policy
Port settings
Network Configuration > Ports > Port Settings
User interface
System > Management Interface > User Interface
Config backup
System > System Management > Configuration Backup and Restore

When to Review These Settings

Hardening should not be treated as a one-time task. These settings should be checked at key points throughout the device lifecycle.

Commissioning

Apply the hardening baseline before the device is connected to the operational network.

Change Control

Review access, services and logging after firmware, network or configuration changes.

Maintenance

Check that passwords, trusted hosts, logging destinations and backup protection are still appropriate.

Audit

Use the checklist as part of periodic security reviews or IEC 62443-aligned documentation work.

Frequently Asked Questions

IEC 62443-4-2 Hardening FAQs

Hardening helps support IEC 62443-4-2 alignment, but it is not the same as product certification. Certification depends on the device, its implemented security capabilities, configuration, documentation and the assessment process. These steps provide a practical baseline for more secure deployment.
Default credentials and community strings are often widely known or easy to obtain. Replacing them reduces the risk of simple unauthorised access and should be one of the first steps during device provisioning.
Sending events and security logs to a central monitoring system helps improve visibility. It also makes it easier to investigate suspicious activity, faults or unexpected changes without relying only on local device logs.
Insecure management interfaces such as HTTP and Telnet should be disabled unless there is a specific operational reason to keep them enabled. Where available, secure alternatives such as HTTPS and SSH should be used instead.
Hardening settings should be reviewed during commissioning, after configuration or firmware changes, and as part of regular maintenance or audit activity. This helps ensure the device remains aligned with the intended security baseline over time.

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