CMMC Enclaves Explained

CMMC Enclaves Explained: A Practical Path to Level 2 Compliance Without Securing Everything

For many defense contractors, CMMC Level 2 feels intimidating. You hear phrases like 110 practices, NIST SP 800‑171, assessment-ready, and DoD assessments, and it can sound like your entire business needs to be rebuilt from the ground up.

Here’s the good news: it probably doesn’t.

Most small and mid-sized organizations do not need to secure their entire enterprise to meet CMMC Level 2. Instead, they can use a focused, defensible strategy called a CMMC enclave—a way to protect Controlled Unclassified Information (CUI) – the sensitive data the DoD wants you to protect – without turning the rest of the business upside down.

Think of it this way: instead of installing airport-style security in your entire office building, you build a secure vault for your valuables. That vault is your enclave.

This article explains what a CMMC enclave really is, how it applies specifically to CMMC Level 2, real-world enclave setup examples, how assessors evaluate them, and how to get started without overengineering your environment.

What Is a CMMC Enclave (in Plain English)?

At its core, a CMMC enclave is a clearly defined environment—technical, physical, or procedural—where CUI is stored, processed, or transmitted, and where all required CMMC Level 2 controls are applied.

Everything inside the enclave is in scope for the assessment. Everything outside is not—as long as CUI cannot flow into it.

An enclave has four essential characteristics:

Defined boundaries
You can clearly explain where the enclave starts and stops.
Authorized access only
Only approved users, devices, and applications can interact with CUI.
Controlled data flow
CUI does not leak into email systems, file shares, personal devices, or shadow IT.
Assessable controls
All Level 2 practices can be demonstrated inside the enclave with evidence.

What an Enclave Is Not

To avoid costly misunderstandings:

An enclave is not hiding data from assessors
It is not skipping controls
It is not automatically created by using GCC High or a cloud provider
It is not a loophole

Assessors expect enclaves—as long as they are well-designed and well-documented.

Why Enclaves Exist in the CMMC Model

CMMC is about trustworthy handling of CUI, not punishing small businesses with enterprise-sized security programs.

The DoD recognizes that:

Many contractors only touch CUI in small parts of the organization
Applying 110 practices across every system is expensive and unnecessary
Segmentation aligns with long-standing cybersecurity principles like least privilege and need-to-know

CMMC Level 2 is directly aligned with NIST SP 800‑171, which already emphasizes scoping, boundary definition, and controlled access.

Business Benefits of Enclaves

For leadership and budget holders, enclaves deliver real advantages:

Reduced assessment scope – fewer systems, fewer controls to prove
Lower implementation cost – security investment is concentrated where it matters
Faster readiness – teams can become compliant in months, not years
Minimal disruption – the rest of the business keeps working as usual

As a simple example: your receptionist does not need access to engineering drawings. An enclave ensures they never have it—and never need controls applied to their workstation.

Common Types of CMMC Enclaves (With Real Examples)

Most organizations use a combination of these enclave types.

1. Technical Enclaves (Most Common)

Technical enclaves rely on IT architecture to isolate CUI.

Typical designs include:

Segmented networks or VLANs
Virtual Desktop Infrastructure (VDI)
Dedicated cloud tenants
Strong identity-based access controls

Example: Engineering VDI Enclave

Engineers access CUI only through a secured virtual desktop
No CUI is stored on local laptops
USB, clipboard, and printing are restricted
MFA is enforced for all access

Outside the VDI, laptops are considered out of scope.

This is one of the most defensible and assessor-friendly enclave designs.

2. Physical Enclaves

Physical enclaves rely on controlled spaces.

Typical designs include:

Locked rooms or labs
Badge-restricted access
Visitors escorted and logged
Stand-alone workstations

Example: Controlled Manufacturing Area

CUI drawings only accessible from locked workstation pods
No phones, cameras, or removable media allowed
Access limited to cleared personnel
Systems not connected to corporate Wi-Fi

Physical enclaves work best in environments with fixed locations and workflows.

3. Administrative / Process Enclaves (Supporting Role)

Administrative controls support enclaves but rarely stand alone.

Examples include:

Defined data handling rules
Formal role definitions
Workflow restrictions
Document marking and routing procedures

Important reality: policies alone do not create an enclave. They must support technical or physical controls.

What Can—and Cannot—Be Inside a CMMC Level 2 Enclave

Understanding scope boundaries is critical.

You Can Include:

CUI repositories
Engineering and technical data
Controlled email or collaboration tools
Secure backup systems

You Cannot Include:

Unrestricted endpoints
Personal devices without controls
Consumer cloud storage
Unauthorized applications or plugins

The Golden Rule of Scoping

If CUI can flow to it, it is in scope.

Assessors will look for technical enforcement, not intention.

How Enclaves Reduce Cost and Complexity

CMMC Level 2 requires 110 practices across 14 domains. Applying those to an entire enterprise is expensive.

Enclaves change the equation.

Cost Difference (Typical Example)

Approach	Systems in Scope	Cost	Complexity
Full Enterprise	200+ endpoints	Very High	High
Enclave-Based	15–30 systems	Manageable	Controlled

Operational Benefits

Non-CUI staff need less training
Fewer controls to document
Smaller evidence packages
Faster remediation cycles

Most importantly: employees outside the enclave can work normally, reducing friction and resistance.

Common Mistakes Organizations Make With CMMC Enclaves

Assessors see these mistakes often.

“We Use GCC High, So We Have an Enclave”

Cloud platforms do not define boundaries by themselves. You must still control users, devices, and data paths.

Uncontrolled Data Flow

Downloading CUI to laptops, emailing it externally, or syncing it to unmanaged tools immediately defeats the enclave.

Overloading the Enclave

Putting everyone in the enclave erases the cost benefit and increases assessment burden.

Weak Identity and Access Management

No MFA, shared accounts, or poor offboarding are instant red flags.

Poor Documentation

If you cannot explain and prove how the enclave works, it may not be accepted.

Real‑World CMMC Enclave Case Studies (Level 2 Aligned)

The concept of a CMMC enclave makes sense on paper—but it’s easiest to understand when you see how real organizations apply it. Below are representative, real‑world enclave scenarios that reflect how defense contractors successfully scope, implement, and defend their environments during CMMC Level 2 readiness and assessments.

Note: These examples are anonymized composites based on common assessment outcomes and assessor feedback. Details are simplified for clarity, but the approaches are realistic and defensible.

Case Study 1: Small Engineering Firm Using a VDI Enclave

Organization Profile

45‑person engineering services firm
Supports DoD prime with design and analysis work
Only 12 users require access to CUI
Limited internal IT staff

The Challenge: Originally, the company assumed they would need to bring all 45 laptops into CMMC Level 2 scope. That would have meant upgrading devices, enforcing technical controls company‑wide, retraining staff, and significantly increasing compliance costs.

The Enclave Strategy: They implemented a technical enclave using Virtual Desktop Infrastructure (VDI):

CUI accessed only through a secured virtual desktop
No CUI stored on local laptops
USB, clipboard, printing, and downloads restricted
Strong MFA on enclave access
Only 12 named users approved for enclave access

All other systems—including finance, HR, and sales laptops—were out of scope because no CUI could flow to them.

Assessment Outcome

Scope reduced from 45 endpoints to 14 systems
Clear enclave boundary diagrams satisfied assessor expectations
Evidence collection focused solely on enclave controls
Assessment completed faster with fewer remediation findings

Key Lesson

VDI‑based enclaves are one of the most assessor‑friendly designs when implemented with strong access controls and documentation.

Case Study 2: Manufacturing Contractor with a Physical Enclave

Organization Profile

120‑employee manufacturing contractor
Produces DoD components based on CUI technical drawings
CUI only accessed on the shop floor
No remote access required for CUI

The Challenge: Management feared that connecting shop‑floor systems to the broader corporate network would dramatically expand scope and cost.

The Enclave Strategy: They created a physical enclave within the manufacturing area:

Locked workstation pods with badge‑controlled access
Systems isolated from corporate Wi‑Fi
No phones, cameras, or removable media permitted
Visitors escorted and logged
Drawings accessed only from designated machines

Administrative policies reinforced behaviors, but physical and technical controls enforced compliance, not policy alone.

Assessment Outcome

Only shop‑floor systems were in scope
Assessors validated physical controls through observation and access reviews
Workforce outside manufacturing remained fully out of scope
Minimal disruption to corporate IT operations

Key Lesson

Physical enclaves can be highly effective for fixed‑location workflows, especially when CUI use is well‑contained.

Case Study 3: Professional Services Firm That Failed — and Recovered

Organization Profile

60‑person professional services contractor
Uses GCC High email and SharePoint
Believed cloud usage alone created an enclave

The Initial Mistake The organization assumed that because CUI lived in GCC High, they automatically had an enclave. In reality:

Users accessed CUI from unmanaged personal laptops
Files were downloaded and shared locally
MFA enforcement was inconsistent
No formal boundary documentation existed

During pre‑assessment readiness review, they discovered:

Nearly the entire enterprise was in scope
Enclave definition was indefensible

The Correction They redesigned the enclave to include:

Managed, hardened endpoints for enclave users
Conditional access restricting CUI access to compliant devices
Clear user lists and access reviews
Data flow diagrams documenting entry and exit points

Final Outcome

Scope reduced from 60 users to 18
Documentation aligned policies, diagrams, and configurations
Organization passed assessment after remediation

Key Lesson

Cloud platforms enable enclaves—but they do not define them. Identity, devices, and data flow must still be controlled.

Case Study 4: Hybrid Enclave for a Distributed Workforce

Organization Profile

80‑employee consulting firm
Mix of office‑based and remote technical staff
CUI accessed intermittently across multiple programs

The Challenge: A fully physical enclave wasn’t feasible, and locking down all endpoints would have been cost‑prohibitive.

The Enclave Strategy: They adopted a hybrid enclave:

VDI enclave for remote staff
On‑prem secured workstations for office users
Centralized identity and access management
Formalized CUI handling workflows

Administrative controls supported the technical design, but technical enforcement prevented data leakage.

Assessment Outcome

Assessors focused on consistency across enclave access methods
Unified access controls simplified evidence collection
Demonstrated scalability as contracts expanded

Key Lesson

Enclaves can be mixed and flexible as long as boundaries are clear and consistently enforced.

What These Case Studies Reveal About Assessor Expectations

Across all successful outcomes, assessors consistently looked for the same things:

A clearly defined enclave boundary
Technical enforcement of access (not trust or policy)
Alignment between diagrams, policies, and system configurations
Proof that CUI cannot leak outside the enclave
Evidence that only authorized users touch CUI

When those elements were present, enclave strategies were not only accepted—they were often encouraged.

Why Case Studies Matter for Your CMMC Strategy

These examples show that:

Enclaves are not theoretical
They work across engineering, manufacturing, and services
Mistakes are common—but correctable
Documentation is just as important as design

Most importantly, they prove that you do not need to over‑secure your entire business to meet CMMC Level 2.

Ready to Build an Enclave That Looks Like These Success Stories?

If you want your organization to be the successful case study—and not the cautionary one:

✅ Schedule a CMMC Enclave Scoping Workshop

We’ll:

Identify exactly where your CUI lives
Define assessor‑defensible boundaries
Design an enclave aligned to CMMC Level 2
Reduce scope, cost, and assessment risk

Prepare smarter. Certify with confidence. Maintain compliance.

How CMMC Assessors Evaluate Enclaves

Assessors do not expect perfection—but they do expect clarity.

What Assessors Focus On

Boundary Definition
Can you clearly explain which systems are in scope and why?
Data Flow Control
How does CUI enter, move within, and exit the enclave?
Access Reviews
Who has access? Why? How is it reviewed?
Implementation of Level 2 Practices
Are all 110 practices addressed inside the enclave?
Evidence Quality
Policies, diagrams, configurations, logs, and user lists must align.

The Assessor’s Core Question

“Show me where CUI lives, who touches it, and how it’s protected.”

If you can answer that confidently and consistently, assessors are typically receptive to enclave strategies.

Is a CMMC Enclave Right for Your Organization?

An enclave is usually a strong fit if:

Fewer than 30–40 users need CUI access
Workflows are well-defined
Leadership wants to control cost
IT maturity is moderate or improving

It may be less ideal if:

CUI is everywhere
Workforce is highly distributed without controls
Foundational security practices are missing

Important: CMMC does not require enclaves. They are a strategy, not a mandate.

Getting Started: First Steps to Building a Defensible Enclave

Start simple and deliberate.

Identify where CUI exists
Map how it flows (users, devices, applications)
Choose the right enclave type
Restrict access aggressively
Document everything

Good documentation turns a technical design into an accepted assessment boundary.

Conclusion: Enclaves Are a Smarter Path to CMMC Level 2

CMMC enclaves are not shortcuts. They are intentional design decisions that align security with real business needs.

When done correctly:

They reduce scope—not accountability
They save money without sacrificing trust
They improve clarity for assessors and staff alike

Smart compliance beats brute‑force compliance—every time.

Ready to Build a Defensible CMMC Enclave?

If you’re preparing for CMMC Level 2 and want to reduce risk, cost, and uncertainty:

✅ Contact us to schedule a CMMC Enclave Scoping Workshop
We’ll identify your CUI, define defensible boundaries, map assessor expectations, and help you design an enclave strategy that actually works.

Prepare smarter. Certify with confidence. Maintain compliance.

Authoritative References for Further Reading

Department of Defense – CMMC Program Overview
NIST SP 800-171 Rev 2: Protecting CUI in Nonfederal Systems
NIST SP 800‑171A Rev 3: Assessment Procedures
DoD CUI Registry
CMMC Level 2 Assessment Guide
FedRAMP Moderate Baseline Documentation
DoD CIO: CMMC Scoping Guidance
The Cyber AB (CMMC Official Site)

About the Author

Daniel Ihonvbere, CISM, CISSP, specializes in CMMC, NIST 800‑171, and DFARS‑aligned security programs for SMBs in the DIB. He focuses on clear governance, defensible evidence, and audit‑ready practices that teams can sustain year‑round.

Connect with Daniel on LinkedIn for CMMC insights | www.techprognosis.com

Disclaimer

This content is for general education and awareness only. Daniel and Tech Prognosis are not a C3PAO, CCP, or CCA and do not provide certification or assessment services. For official certification decisions, organizations must engage an authorized Cyber‑AB C3PAO and follow the CMMC Assessment Process (CAP).