DoD OT Zero Trust Alignment

Trout Access Gate (TAG) is an on-premise appliance that enables Target-Level Zero Trust in operational technology environments.

Without rewiring, downtime, agents, or redesign.

Why the DoD shift matters in OT

The DoD is mandating a move from “trusted networks” to continuous authentication and fine-grained policy enforcement, including for OT control systems.

The guidance also states that applying standard IT security approaches to OT can be ineffective (and even dangerous), because OT environments rely on legacy equipment, industrial protocols, and strict safety/availability constraints.

TAG was designed for exactly these constraints.

What Trout delivers

Zero Trust without industrial disruption

Modernize security around legacy and unpatchable OT systems while keeping operations unchanged.

Proxy + SDN overlay (built for OT)

TAG uses a software-defined networking (SDN) overlay to insert a lightweight proxy in front of existing OT assets

Practical procurement and scale

One appliance per site with predictable, site-based pricing.

Proven in real production environments

Battle-tested with unpatchable, mission-critical systems.

Trout Solution

DoD OT Zero Trust coverage

Users

  • Identity-based access for all OT interactions

  • Least-privilege, role- and attribute-based controls at the asset level

  • Multi-factor authentication for OT access

  • Fully audited, time-bound access for operators, administrators, OEMs, and contractors

Devices

  • Central inventory of OT devices and non-person entities

  • Deny-by-default communications enforced at each asset

  • Compensating identity controls for legacy devices without certificates

  • OT-safe behavioral monitoring for unpatchable systems

Applications & Workloads

  • Inventory of OT applications and engineering tools interacting with assets

  • Authorization enforced before sensitive actions (logic changes, firmware, recipes)

  • Attribute-based access control even for legacy applications

  • Full attribution of every command to a user, session, and policy

Data

  • Characterization of OT data flows per asset

  • Standardized tagging and labeling of OT data

  • Protection of critical configuration and control files

  • Data-loss prevention enforced at the OT boundary with full logging

Networks & Micro-segmentation

  • Per-asset, per-protocol, per-command enforcement based on identity and role

  • Mapping and monitoring of OT data flows

  • Segmentation of control, data, and management planes

  • Micro-DMZs created per asset without network redesign

Automation and Orchestration

  • Centralized catalog of Zero Trust attributes and policies

  • Consistent enforcement across multiple sites

  • Version-controlled policy management

  • Logged and governed policy changes aligned with OT change control

Visibility & Analytics

  • Continuous monitoring of OT access, commands, and flows

  • OT-aware anomaly detection for users and devices

  • Unified telemetry combining identity, policy, and protocol data

  • Automated response options such as command blocking or asset isolation

Background

Get in Touch with Trout team

Enter your information and our team will be in touch shortly.

Background

Get in Touch with Trout team

Enter your information and our team will be in touch shortly.

FAQ

DoD OT Zero Trust FAQ: Access Control, Legacy Systems, and Compliance

What DoD guidance does Trout align with?

Trout aligns with the Department of Defense Zero Trust for Operational Technology (OT): Activities and Outcomes, including the requirements mandated under DTM 25-003, which require Target-Level Zero Trust across OT systems.

What DoD guidance does Trout align with?

Trout aligns with the Department of Defense Zero Trust for Operational Technology (OT): Activities and Outcomes, including the requirements mandated under DTM 25-003, which require Target-Level Zero Trust across OT systems.

Is Trout a firewall or a traditional OT security appliance?

No. Trout is a Zero Trust enforcement appliance designed specifically for OT. It does not rely on perimeter firewalls, network redesign, or agent-based controls. Instead, it enforces identity, authorization, and segmentation directly at the OT asset boundary.

Is Trout a firewall or a traditional OT security appliance?

No. Trout is a Zero Trust enforcement appliance designed specifically for OT. It does not rely on perimeter firewalls, network redesign, or agent-based controls. Instead, it enforces identity, authorization, and segmentation directly at the OT asset boundary.

Does deploying Trout require changes to the existing OT network?

No. Trout does not require: Rewiring or recabling VLAN or routing changes Firewall redesign Changes to PLCs, HMIs, or legacy devices The existing OT network remains unchanged.

Does deploying Trout require changes to the existing OT network?

No. Trout does not require: Rewiring or recabling VLAN or routing changes Firewall redesign Changes to PLCs, HMIs, or legacy devices The existing OT network remains unchanged.

How does Trout work with legacy or unpatchable systems?

Trout is designed for environments where devices: Cannot be patched Cannot run agents Cannot support certificates or modern identity protocols In these cases, Trout provides compensating identity and authorization controls at the boundary, allowing Zero Trust enforcement without modifying the device itself.

How does Trout work with legacy or unpatchable systems?

Trout is designed for environments where devices: Cannot be patched Cannot run agents Cannot support certificates or modern identity protocols In these cases, Trout provides compensating identity and authorization controls at the boundary, allowing Zero Trust enforcement without modifying the device itself.

How is access controlled in practice?

All access to protected OT assets—local or remote—passes through Trout. Before access is granted, Trout enforces: Identity verification Role- and attribute-based authorization Time-bound and task-specific permissions Every session and command is logged and attributable.

How is access controlled in practice?

All access to protected OT assets—local or remote—passes through Trout. Before access is granted, Trout enforces: Identity verification Role- and attribute-based authorization Time-bound and task-specific permissions Every session and command is logged and attributable.

Can Trout enforce least privilege in OT environments?

Yes. Trout enforces deny-by-default access and allows only explicitly authorized users, devices, applications, protocols, and commands—down to the asset level. This enables practical least-privilege enforcement even in flat or legacy OT networks.

Can Trout enforce least privilege in OT environments?

Yes. Trout enforces deny-by-default access and allows only explicitly authorized users, devices, applications, protocols, and commands—down to the asset level. This enables practical least-privilege enforcement even in flat or legacy OT networks.

How does Trout support contractors and OEM access?

Trout provides: Identity-verified access for third parties Time-limited and scoped permissions Full audit logs of sessions and actions This allows controlled vendor access without persistent credentials or shared accounts.

How does Trout support contractors and OEM access?

Trout provides: Identity-verified access for third parties Time-limited and scoped permissions Full audit logs of sessions and actions This allows controlled vendor access without persistent credentials or shared accounts.

DoD OT Zero Trust summary

CMMC for OT and Legacy

DoD OT Zero Trust Summary - Practical Compliance Without Disrupting Operations

The Department of Defense is mandating a shift to Zero Trust for operational technology, including legacy and mission-critical systems that cannot be modified or modernized. Traditional IT security approaches are often ineffective in these environments and can introduce operational risk.

Trout Access Gate enables Target-Level Zero Trust in OT without disrupting operations. A single on-premise appliance per site inserts an identity-aware enforcement boundary in front of existing assets using a software-defined overlay. This allows identity-based access control, least privilege, micro-segmentation, and full auditability ; without rewiring, agents, downtime, or changes to PLCs, HMIs, or industrial networks.

Trout provides a practical path to DoD OT Zero Trust compliance by enforcing security at the asset boundary, where attacks occur, while preserving the safety, availability, and stability of operational systems.