What this requirement asks
Implement subnetworks for publicly accessible system components that are physically or logically separated from internal networks.
This is a CMMC Level 2 requirement in the System & Communications Protection family, drawn from NIST SP 800-171 Rev. 2. An assessor evaluates it objective by objective — every objective below must be supported by evidence, not just described in a policy.
Assessment objectives (2)
- 3.13.5[a] — publicly accessible system components are identified
- 3.13.5[b] — subnetworks for publicly accessible system components are physically or logically separated from internal networks
What an assessor examines
Examine:
- System and communications protection policy
- procedures addressing boundary protection
- system security plan
- list of key internal boundaries of the system
- system design documentation
- boundary protection hardware and software
- system configuration settings and associated documentation
- enterprise security architecture documentation
- system audit logs and records
- other relevant documents or records
Interview:
- System or network administrators
- personnel with information security responsibilities
- system developers
- personnel with boundary protection responsibilities
Test:
- Mechanisms implementing boundary protection capability
Evidence that defends it
Show default-deny rules and explicit permits
Check your readiness
Score this requirement against your own environment with the Level 2 self-assessment checklist, or estimate your SPRS score with the free CMMC compliance tool. Self-reported answers are planning signals only — they do not establish a verified or assessor-accepted result.