SC.L2-3.13.6 — Deny network traffic by default, allow by exception
Deny network communications traffic by default and allow network communications traffic by exception (i.e., deny all, permit by exception).
Verbatim NIST SP 800-171 Rev 2 requirement text (3.13.6).
How it's scored
5 points deducted from your SPRS score if unmet.
An open gap here is not POA&M-eligible (only 1-point requirements qualify under 32 CFR 170.21, with one narrow exception at SC.L2-3.13.11): it must be fully implemented before a Level 2 assessment can certify.
What an assessor checks: the 2 assessment objectives
NIST SP 800-171A determination statements, verbatim. A CMMC Level 2 assessor marks SC.L2-3.13.6 MET only when every applicable objective is satisfied — and examines evidence, not assertions.
| Objective | Determination statement |
|---|---|
| 3.13.6[a] | network communications traffic is denied by default. |
| 3.13.6[b] | network communications traffic is allowed by exception. |
Where do you stand on SC.L2-3.13.6?
The free Muster Score walks all 110 requirements — including every objective above — and computes your exact SPRS score in your browser. No signup, no upload, and your answers never leave your device.
Get your free Muster Score →Requirement and objective text: NIST SP 800-171 Rev 2 / SP 800-171A (verbatim). Scoring: DoD Assessment Methodology v1.2.1; POA&M eligibility: 32 CFR 170.21. Muster is independent and not affiliated with the U.S. Department of Defense or the Cyber AB; this page is compliance information, not legal advice or a certification.