CMMC Navigatorby Foxx Cyber Bedrock CMMC

↑↓ to move, Enter to open, Esc to close. Try 3.5.3, AC.L2-3.1.1, MFA or unmarked.

3.13.5Put public services in their own subnet in Rev. 3

Withdrawn and incorporated elsewhere: 03.13.01 Boundary Protection.

Status as of 2026-09-08

Rev. 2 is what a contract requires today. DFARS 252.204-7012 and the CMMC rule at 32 CFR 170 point at NIST SP 800-171 Rev. 2, and a standing DoD class deviation keeps it there. NIST has published Rev. 3, but publishing a revision does not change an obligation. A move to Rev. 3 would arrive through the Department's reform process and formal rulemaking, a change to that deviation or an amendment to the rule, not through publication. The Department has published its organization-defined parameter values for Rev. 3 in preparation; that is groundwork, not adoption.

Side by side

Rev. 2 · in force 3.13.5 Public-Access System Separation

Implement subnetworks for publicly accessible system components that are physically or logically separated from internal networks.

Assessment objectives · 800-171A

  1. [a] publicly accessible system components are identified
  2. [b] subnetworks for publicly accessible system components are separated from internal organizational networks

Rev. 3 · not adopted 03.13.01 Boundary Protection

a. Monitor and control communications at external managed interfaces to the system and key internal managed interfaces within the system.

b. Implement subnetworks for publicly accessible system components that are physically or logically separated from internal networks.

c. Connect to external systems only through managed interfaces that consist of boundary protection devices arranged in accordance with an organizational security architecture.

Determination statements · 800-171A Rev. 3

  1. 03.13.01.a[01] communications at external managed interfaces to the system are monitored.
  2. 03.13.01.a[02] communications at external managed interfaces to the system are controlled.
  3. 03.13.01.a[03] communications at key internal managed interfaces within the system are monitored.
  4. 03.13.01.a[04] communications at key internal managed interfaces within the system are controlled.
  5. 03.13.01.b subnetworks are implemented for publicly accessible system components that are physically or logically separated from internal networks.
  6. 03.13.01.c external system connections are only made through managed interfaces that consist of boundary protection devices arranged in accordance with an organizational security architecture.

Draws on Rev. 2 3.13.1, 3.13.5.

Left: NIST SP 800-171 Rev. 2 and 800-171A, verbatim. Right: NIST SP 800-171 Rev. 3 and 800-171A Rev. 3, verbatim, with organization-defined blanks highlighted.

Word by word

The Rev. 2 requirement compared with its Rev. 3 successor. A mechanical comparison of the two verbatim texts, not an interpretation.

removed in Rev. 3 added in Rev. 3

Rev. 2 3.13.5 → Rev. 3 03.13.01 Boundary Protection

Monitor and control communications at external managed interfaces to the system and key internal managed interfaces within the system. Implement subnetworks for publicly accessible system components that are physically or logically separated from internal networks. Connect to external systems only through managed interfaces that consist of boundary protection devices arranged in accordance with an organizational security architecture.

16 words kept, 0 removed, 41 added. Rev. 3 statement labels omitted for the comparison.

What NIST says changed

Rev. 3 withdraws this requirement as a separate item and folds it into another requirement. NIST's note: Incorporated into 03.13.01.

NIST's Rev. 3 discussion for 03.13.01

Managed interfaces include gateways, routers, firewalls, network-based malicious code analysis, virtualization systems, and encrypted tunnels implemented within a security architecture. Subnetworks that are either physically or logically separated from internal networks are referred to as demilitarized zones or DMZs. Restricting or prohibiting interfaces within organizational systems includes restricting external web traffic to designated web servers within managed interfaces, prohibiting external traffic that appears to be spoofing internal addresses, and prohibiting internal traffic that appears to be spoofing external addresses.

What this means for you now

Nothing changes in what you are assessed against until a class deviation or a published rule adopts Rev. 3. Keep meeting 3.13.5 as written in Rev. 2.

Bedrock CMMC shows this same comparison against your own package, with your current status on the Rev. 2 side, so the day adoption lands the migration is a review, not a rewrite.

Back to the Rev. 2 vs Rev. 3 overview

Where this page's facts come from
Rev. 2 text and objectives
bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.basicRequirement@rev2; bedrock-cmmc-api@89b8e8e:migrations/005_reference_objectives.sql#AssessmentObjective.description@rev2
Mapping and change class
bedrock-cmmc-api@89b8e8e:docs/reference/nist-800-171-rev3/normalized/r2_r3_transition_map.json#r2_to_r3
Rev. 3 03.13.01
bedrock-cmmc-api@89b8e8e:docs/reference/nist-800-171-rev3/normalized/rev3.json#requirements[]