Level 2 · System and Communications Protection
SC.L2-3.13.7
Split Tunneling
Remote connectivity should prevent the prohibited simultaneous path to organizational and external networks.
Official reference
The requirement
Prevent remote devices from simultaneously establishing non-remote connections with organizational systems and communicating via some other connection to resources in external networks (i.e., split tunneling).
DoD CMMC Assessment Guide, Level 2, version 2.13. SC.L2-3.13.7; requirement and objectives, printed page 225 ↗
Assessment objectives
What must be established
Determine if each applicable objective is satisfied. The labels below follow the cited DoD assessment guide.
- [a]
remote devices are prevented from simultaneously establishing non-remote connections with the system and communicating via some other connection to resources in external networks (i.e., split tunneling).
MET requires evidence that all applicable objectives are satisfied. Final, approved evidence is needed. A NOT APPLICABLE determination needs a scope-based basis and is equivalent to MET for scoring. Enduring exceptions and temporary deficiencies have specific conditions under 32 CFR 170.24; they are not a general permission to defer implementation.
GAVII Cybersecurity assessment approach
Connect the objective to the evidence
Inspect the actual routing behavior of remote devices, not only the VPN profile name. Include exceptions, local-network access, and relevant alternate interfaces in the review.
Assessment focus: objectives [a]. Use the methods together; a single example does not establish every objective.
Examine
Review remote-access routing policies, client configuration, and exception decisions.
Interview
What external connectivity remains available while a remote device is connected to the organizational system?
Demonstrate or test
Inspect routes and safe connectivity tests during a representative remote session to verify the intended restriction.
Evidence gaps to look for
- A full-tunnel policy is assigned but bypass routes remain.
- An alternate interface defeats the intended restriction.
GAVII Cybersecurity’s examples illustrate ways to examine, interview, and test. They are not a mandatory artifact list or a guarantee of an assessment result. Combine methods and address every applicable objective in the actual scope.
Assessment constraints
Scoring and POA&M eligibility
Score: 1
If this requirement is NOT MET, deduct 1 point from the Level 2 maximum of 110. The deduction applies to the requirement, not separately to each objective.
Scoring rule ↗POA&M: Eligible
Potentially eligible only if all Conditional Level 2 criteria are satisfied, including a score of at least 88 out of 110 and timely closeout. Eligibility is not a finding that this requirement is MET.
POA&M rule ↗Conditional Level 2 requires a score of at least 88 out of 110 and satisfaction of every eligibility condition. A 1-point requirement is not automatically eligible. The permitted POA&M must be closed through the appropriate closeout assessment within 180 days of the Conditional CMMC Status Date. An operational remediation plan does not confer Conditional Status.
Assessment planning
Location and observation
Not specifically listed in CAP P.11
This requirement is not specifically listed in CAP P.11. That does not establish that remote assessment is sufficient: the Lead CCA and C3PAO determine an adequate approach for the actual scope and evidence.
CAP §P.11, pages 10–11 ↗Check the source
References and related requirements
- DoD CMMC Assessment Guide, Level 2 ↗SC.L2-3.13.7; requirement and objectives, printed page 225. 2.13, September 2024.
- 32 CFR 170.24: Assessment findings and scoring ↗170.24(b) and (c)(2). Current electronic Code of Federal Regulations.
- 32 CFR 170.21: POA&M eligibility and closeout ↗170.21(a)(2) and (b). Current electronic Code of Federal Regulations.
- NIST SP 800-171 Rev. 2 ↗Requirement 3.13.7. February 2020, updated January 2021.
- NIST SP 800-171A ↗Assessment procedure 3.13.7. June 2018.
- Cyber AB CMMC Assessment Process (CAP) ↗P.11, printed pages 10-11; Level 2 certification assessment-location planning. 2.0, December 2024.
Program timing and contract applicability can change independently of these requirements. Check current DoD program notices and your solicitation or contract before making a compliance decision. Open the official DoD resource hub.