CMMC Level 2 Practice 3.14.6: Monitor organizational systems, including inbound and outbound communications traffic, to

CMMC Level 2 Practice 3.14.6 requires you to continuously monitor organizational systems and network communications (inbound and outbound) so you can detect and respond to suspicious activity affecting CUI environments. To operationalize it fast, define monitoring scope, centralize logs, set alert thresholds, run daily triage, and retain evidence that monitoring operates as designed. ¹

Key takeaways:

• Scope monitoring to the CUI boundary first, then expand to supporting enterprise services that can access or route CUI traffic. ¹
• “Monitoring” must produce actionable detection: collected logs, correlation/alerting, triage, escalation, and documented response outcomes. ¹
• Assessment readiness depends on recurring evidence: configurations, alert samples, tickets, review attestations, and log-retention proof. ²

A CMMC Level 2 assessment will not accept “we have a firewall” as proof of monitoring. For Practice 3.14.6, you need to show that inbound and outbound communications traffic is observed, that suspicious patterns are detected, and that your team actually reviews and acts on the signal. The fastest way to get this right is to treat it like an operational control: defined scope, defined data sources, defined detection content, and a repeatable review and escalation routine.

This requirement matters most at the boundaries where CUI can enter or leave your environment: internet egress, remote access, email, DNS, cloud service access, and administrative pathways. The goal is to reduce dwell time for intrusions and stop data exfiltration or command-and-control activity before it becomes a reportable incident. Your evidence needs to prove two things: (1) you can see relevant traffic and events, and (2) you consistently respond to what you see.

This page translates CMMC Level 2 Practice 3.14.6 into implementable steps, artifacts to retain, and the audit questions you will get. It aligns to NIST SP 800-171 Rev. 2 and the CMMC program context. ^{1 3 2}

Regulatory text

Provided excerpt: “CMMC Level 2 practice mapped to NIST SP 800-171 Rev. 2 requirement 3.14.6 (Monitor organizational systems, including inbound and outbound communications traffic, to).” ¹

What the operator must do

You must implement monitoring across organizational systems with explicit coverage of inbound and outbound communications traffic. Practically, that means:

• Collecting security-relevant telemetry (network and host) from the CUI environment and its boundary controls.
• Detecting anomalous or unauthorized activity through alerts, correlation, or rule-based detections.
• Reviewing alerts/events and routing them into an incident handling workflow.
• Retaining evidence that monitoring is configured, operating, and reviewed on a recurring basis. ¹

Plain-English interpretation

This practice expects you to watch the roads in and out of your environment and key internal intersections, then act when something looks wrong. Inbound monitoring focuses on attempted compromise (scans, exploit attempts, suspicious authentication patterns). Outbound monitoring focuses on exfiltration, malware callback, and unauthorized data movement (unexpected destinations, unusual protocols, large transfers, repeated DNS beacons).

A common assessment failure is “log collection without operational use.” If you cannot show triage actions, escalation decisions, and remediation outcomes tied to alerts, the assessor can conclude monitoring is not effective even if tools exist. ²

Who it applies to

Entities: Defense contractors and federal contractors handling CUI that are in scope for CMMC Level 2. ³
Operational context: Any environment that stores, processes, or transmits CUI, plus supporting services that can access, route, or administer that environment (for example: identity provider, remote access, security tooling, boundary firewall, cloud tenant controls). ¹

Applies across:

• On-prem networks and enclaves supporting CUI
• Cloud workloads in scope for CUI
• Remote access paths (VPN/ZTNA) into the CUI environment
• Internet egress points used by CUI systems
• Email and collaboration systems used to send/receive CUI (where applicable)

What you actually need to do (step-by-step)

Step 1: Define monitoring scope and the CUI boundary

Document:

• The CUI system boundary (networks, subnets, cloud accounts/projects, endpoints, applications).
• The ingress/egress points (firewalls, secure web gateway/proxy, VPN/ZTNA, email gateways, DNS resolvers, cloud egress).
• “Monitoring in scope” vs. “out of scope,” with rationale tied to CUI data flows. ¹

Operator tip: If you can’t confidently map CUI data flows, you will struggle to justify why certain traffic is monitored and other traffic is not.

Step 2: Identify required telemetry sources (minimum viable set)

Create a log source register covering:

• Network: firewall traffic logs, IDS/IPS alerts (if present), proxy/SWG logs, VPN/ZTNA logs, DNS logs, netflow (if available).
• Identity: authentication logs (SSO/IdP), privileged access logs, directory audit logs.
• Endpoint: EDR alerts, Windows/Linux audit logs (or equivalent), server/application security logs.
• Cloud/SaaS: control plane audit logs and network/security telemetry for in-scope services. ¹

Step 3: Centralize logs and protect their integrity

Implement a central collection and analysis approach (often a SIEM or SIEM-like platform) with:

• Time sync (so events correlate correctly).
• Role-based access to logs and detections.
• Controls to reduce tampering risk (restricted deletion, audit trails, immutable storage where feasible). ¹

Daydream fit: Daydream is most useful here as the control-operations layer: mapping 3.14.6 to owners, log sources, review cadence, and recurring evidence capture so you can prove the control runs consistently during the assessment window. ²

Step 4: Implement detection content for inbound and outbound traffic

You need detections that clearly relate to inbound/outbound monitoring, such as:

• Inbound: repeated failed logins to remote access, suspicious geolocation access (if you track it), port scans, IDS exploit signatures, abnormal admin access attempts.
• Outbound: unusual destination domains, DNS tunneling indicators, large outbound transfers from servers that usually don’t transmit externally, outbound connections to known bad categories if your tools support reputation feeds.

Keep this practical: start with high-signal alerts you can operationally triage, then expand. ¹

Step 5: Establish daily triage and escalation workflow

Write a short SOP that answers:

• Who reviews alerts (primary and backup).
• What “review complete” means (acknowledged, investigated, closed with reason).
• How you escalate (incident ticket, severity rubric, who approves containment).
• What you do after containment (root cause, recovery, corrective actions).

Tie the SOP to your incident handling process so monitoring leads to action. ¹

Step 6: Tune, test, and document “monitoring works”

Run a repeatable validation activity:

• Generate a known event (test malware simulation in a safe lab, controlled port scan, simulated suspicious DNS query) and confirm it appears in central logs and triggers the right alert.
• Document the test, the result, and any tuning actions.

Assessors like evidence that detections are not theoretical. ²

Step 7: Operationalize retention and recurring evidence capture

Define:

• What log categories you retain (security logs, firewall traffic logs, VPN logs, EDR alerts).
• How you prove retention (storage policy settings, screenshots, platform retention configuration, sample exports).
• How you prove review (tickets, analyst notes, weekly sign-off, alert metrics without making numeric claims).

This is the difference between “configured” and “operating.” ¹

Required evidence and artifacts to retain

Keep artifacts in an assessor-ready folder mapped to Practice 3.14.6:

Core documents

• Monitoring policy/standard referencing inbound and outbound traffic monitoring scope. ¹
• Network and system boundary diagram(s) showing ingress/egress points. ¹
• Logging architecture diagram and log source register. ¹
• SOC/IT monitoring SOP: triage, escalation, handoff to incident response. ¹

System evidence (screenshots/exports)

• SIEM/log platform configuration showing connected sources and retention settings. ¹
• Firewall/proxy/VPN log settings showing traffic logging enabled. ¹
• Detection/alert rule list aligned to inbound/outbound scenarios. ¹

Operational evidence

• Alert samples with investigation notes (sanitize sensitive data). ²
• Tickets for investigated alerts, including closure rationale and corrective actions. ²
• Review attestations (for example: weekly monitoring review sign-off by the responsible role). ²
• Test records showing monitoring catches a known event and your team responds. ²

Common exam/audit questions and hangups

Expect assessors to probe for these specifics:

• “Show me inbound and outbound monitoring.” They will ask for firewall/proxy/DNS logs and examples of outbound detections, not only endpoint alerts. ¹
• “What’s in scope for CUI?” If your boundary is fuzzy, monitoring coverage will look arbitrary. ¹
• “Who reviews alerts and how often?” If the answer is “when we have time,” you will struggle to show operation. ²
• “Prove you acted.” They will want to see tickets and outcomes, not just dashboards. ²

Frequent implementation mistakes and how to avoid them

Mistake	Why it fails in assessments	Fix
Logging only on endpoints, not at network boundaries	Doesn’t demonstrate inbound/outbound communications monitoring	Add firewall/proxy/VPN/DNS logs to central collection; show sample investigations. 1
“We collect logs” but no triage workflow	Control appears non-operational	Define an SOP, assign owners, require closure notes in tickets. 2
Monitoring scope doesn’t match CUI boundary	Assessor can’t confirm coverage	Document boundary and data flows; map each ingress/egress point to a log source. 1
Alert fatigue causes ignored alerts	Operationally, you stop reviewing	Start with high-signal rules, tune, document tuning decisions, and show consistent review artifacts. 2
No evidence retention discipline	You can’t prove prior operation	Set retention configurations and export samples regularly into an evidence repository. 2

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this specific practice. From a risk perspective, weak inbound/outbound monitoring raises the likelihood that compromise or data exfiltration goes undetected long enough to impact CUI confidentiality and contract performance. Under the CMMC program, inability to demonstrate required practices can affect eligibility for contracts that require Level 2 certification. ^{3 2}

Practical 30/60/90-day execution plan

First 30 days: Get to “defensible minimum”

• Confirm the CUI boundary and list all ingress/egress points. ¹
• Stand up central log collection for firewall/VPN and endpoint alerts; document what is connected. ¹
• Publish a one-page monitoring SOP with roles, triage steps, and escalation path. ¹
• Start saving weekly evidence: alert samples, tickets, and a brief review sign-off. ²

Days 31–60: Improve detection quality and show operations

• Add proxy/SWG and DNS logs if outbound visibility is incomplete. ¹
• Build a small set of inbound/outbound detections tied to real threats you can explain. ¹
• Run a controlled monitoring test and document end-to-end detection-to-ticket flow. ²
• Implement an evidence capture routine in Daydream (control mapping, owners, recurring tasks, evidence checklist). ²

Days 61–90: Make it assessment-ready

• Tune detections and document tuning decisions and exceptions. ²
• Confirm log retention settings and access controls; capture screenshots and exports as evidence. ¹
• Conduct an internal tabletop using recent alerts and show how monitoring feeds incident handling. ¹
• Perform a mock interview: “show inbound monitoring,” “show outbound monitoring,” “show proof of review,” and package artifacts accordingly. ²

Frequently Asked Questions

Does 3.14.6 require a SIEM?

The requirement is monitoring and visibility, not a specific tool. A SIEM is the most common way to centralize and correlate logs, but you can meet the intent with other tooling if you can prove coverage, alerting, review, and retention. ¹

What counts as “inbound and outbound communications traffic” for assessors?

Assessors typically expect boundary telemetry such as firewall, VPN/ZTNA, proxy/SWG, and DNS logs, plus evidence you review and act on events tied to those channels. Endpoint-only monitoring rarely demonstrates outbound traffic monitoring by itself. ¹

How do we scope monitoring in a segmented enclave model?

Start with the enclave boundary: all ingress/egress points and administrative access paths. Then include shared enterprise services that can authenticate to, administer, or route traffic for the enclave. Document the rationale in your boundary and log source register. ¹

Can we meet 3.14.6 if a third party provides SOC monitoring?

Yes, but you still own compliance. Keep the third party’s monitoring scope statement, alert/ticket outputs, escalation SLAs you follow internally, and evidence you review outcomes and drive corrective actions. ²

What evidence is most convincing during a CMMC Level 2 assessment?

A clean chain from configuration to operation: log source configs, SIEM/monitoring dashboards, alert rules, real alert investigations with tickets, and review sign-offs showing the process runs routinely. Package it by “inbound” and “outbound” examples. ²

How do we avoid over-collecting logs and drowning the team?

Treat logging and alerting separately. Collect broadly at key boundaries, then alert narrowly with high-signal detections you can triage; tune and expand as your process matures. Document tuning decisions so assessors see intent and control ownership. ¹

Footnotes

1. NIST SP 800-171 Rev. 2

2. DoD CMMC Program Guidance

3. 32 CFR Part 170