NET-03: Boundary Protection
Mechanisms exist to monitor and control communications at the external network boundary and at key internal boundaries within the network.
Control Question: Does the organization monitor and control communications at the external network boundary and at key internal boundaries within the network?
General (47)
| Framework | Mapping Values |
|---|---|
| AICPA TSC 2017:2022 (used for SOC 2) (source) | CC6.1 CC6.1-POF5 CC6.6 CC6.6-POF1 CC6.6-POF3 CC6.6-POF4 CC6.8 |
| CIS CSC 8.1 | 9.6 13.5 |
| CIS CSC 8.1 IG2 | 9.6 13.5 |
| CIS CSC 8.1 IG3 | 9.6 13.5 |
| CSA IoT SCF 2 | IOT-10 |
| GovRAMP | SC-07 |
| GovRAMP Core | SC-07 |
| GovRAMP Low | SC-07 |
| GovRAMP Low+ | SC-07 |
| GovRAMP Moderate | SC-07 |
| GovRAMP High | SC-07 |
| IEC 62443-2-1 2024 | NET 1.3 |
| IEC 62443-3-3 2013 | SR 5.2 |
| IEC 62443-4-2 2019 | CR 5.2 NDR 5.2 |
| ISO 27002 2022 | 8.20 8.21 |
| ISO 27017 2015 | 13.1.1 13.1.2 |
| ISO 27018 2025 | 8.20 8.21 |
| MITRE ATT&CK 16 | T1001 T1001.001 T1001.002 T1001.003 T1008 T1020.001 T1021.001 T1021.002 T1021.003 T1021.005 T1021.006 T1029 T1030 T1036.008 T1041 T1046 T1048 T1048.001 T1048.002 T1048.003 T1055 T1055.001 T1055.002 T1055.003 T1055.004 T1055.005 T1055.008 T1055.009 T1055.011 T1055.012 T1055.013 T1055.014 T1068 T1071 T1071.001 T1071.002 T1071.003 T1071.004 T1071.005 T1072 T1078 T1080 T1090 T1090.001 T1090.002 T1090.003 T1095 T1098 T1098.001 T1102 T1102.001 T1102.002 T1102.003 T1104 T1105 T1114 T1114.003 T1132 T1132.001 T1132.002 T1133 T1136 T1136.002 T1136.003 T1176 T1187 T1189 T1190 T1197 T1199 T1203 T1204 T1204.001 T1204.002 T1204.003 T1205 T1205.001 T1210 T1211 T1212 T1218 T1218.012 T1218.015 T1219 T1221 T1482 T1489 T1498 T1498.001 T1498.002 T1499 T1499.001 T1499.002 T1499.003 T1499.004 T1505.004 T1530 T1537 T1542 T1542.004 T1542.005 T1552 T1552.001 T1552.004 T1552.005 T1552.007 T1557 T1557.001 T1557.002 T1557.003 T1557.004 T1559 T1559.001 T1559.002 T1560 T1560.001 T1563 T1563.002 T1565 T1565.001 T1565.003 T1566 T1566.001 T1566.002 T1566.003 T1567 T1567.001 T1567.002 T1567.003 T1567.004 T1568 T1568.002 T1570 T1571 T1572 T1573 T1573.001 T1573.002 T1590.002 T1598 T1598.001 T1598.002 T1598.003 T1599 T1599.001 T1602 T1602.001 T1602.002 T1609 T1610 T1611 T1612 T1613 T1622 T1648 T1659 |
| MPA Content Security Program 5.3.1 | TS-2.0 |
| NIST 800-53 R4 | SC-7 SC-7(9) SC-7(11) |
| NIST 800-53 R5.2 | SC-07 SC-07(09) SC-07(11) |
| NIST 800-53B R5 (low) (source) | SC-07 |
| NIST 800-53B R5 (moderate) (source) | SC-07 |
| NIST 800-53B R5 (high) (source) | SC-07 |
| NIST 800-82 R3 | SC-07 SC-07(09) SC-07(11) |
| NIST 800-82 R3 LOW OT Overlay | SC-07 |
| NIST 800-82 R3 MODERATE OT Overlay | SC-07 |
| NIST 800-82 R3 HIGH OT Overlay | SC-07 |
| NIST 800-160 Vol2 R1 | SC-07 SC-07(11) |
| NIST 800-161 R1 | SC-7 |
| NIST 800-161 R1 C-SCRM Baseline | SC-7 |
| NIST 800-161 R1 Flow Down | SC-7 |
| NIST 800-161 R1 Level 2 | SC-7 |
| NIST 800-171 R2 (source) | 3.13.1 |
| NIST 800-171 R3 (source) | 03.01.12.a 03.01.18.a 03.13.01.a 03.13.01.b 03.13.01.c |
| NIST 800-171A (source) | 3.13.1[a] 3.13.1[b] 3.13.1[c] 3.13.1[d] 3.13.1[e] 3.13.1[f] 3.13.1[g] 3.13.1[h] |
| NIST 800-171A R3 (source) | A.03.01.18.a[03] A.03.13.01.a[02] A.03.13.01.a[04] A.03.13.01.b A.03.13.01.c |
| NIST 800-172 R3 | 03.01.12E 03.13.04E |
| NIST 800-172A R3 | A.03.01.12E.ODP[01] DS-A.03.13.04E |
| PCI DSS 4.0.1 (source) | 1.3.3 1.4 1.4.1 1.4.2 11.5.1 |
| PCI DSS 4.0.1 SAQ A-EP (source) | 1.3.3 1.4.1 1.4.2 11.5.1 |
| PCI DSS 4.0.1 SAQ B-IP (source) | 1.3.3 1.4.2 |
| PCI DSS 4.0.1 SAQ C (source) | 1.3.3 |
| PCI DSS 4.0.1 SAQ C-VT (source) | 1.3.3 |
| PCI DSS 4.0.1 SAQ D Merchant (source) | 1.3.3 1.4.1 1.4.2 11.5.1 |
| PCI DSS 4.0.1 SAQ D Service Provider (source) | 1.3.3 1.4.1 1.4.2 11.5.1 |
| SWIFT CSF 2025 | 1.5 |
US (19)
EMEA (13)
| Framework | Mapping Values |
|---|---|
| EMEA Germany C5 2026 | COS-02.01B.4 COS-03.02B COS-04.01B COS-04.01AS |
| EMEA Spain CCN-STIC 825 | op.mon.1 mp.com.1 mp.com.2 mp.com.3 |
| EMEA EU DORA RTS 2024 | Article 13.1(g) Article 35.1(c) |
| EMEA UK Cyber Essentials 3.3 | 1.0 |
| EMEA UK DEFSTAN 05-138 2024 | 2427 |
| EMEA UK DEFSTAN 05-138 - L1 2024 | 2427 |
| EMEA UK DEFSTAN 05-138 - L2 2024 | 2427 |
| EMEA UK DEFSTAN 05-138 - L3 2024 | 2427 |
| EMEA Israel CDMO 2.0 | Appendix A, 7.3 |
| EMEA Saudi Arabia IoT CGIoT-1 2024 | 2-4-5 |
| EMEA Saudi Arabia CSCC-1 2019 | 2-4-1-5 |
| EMEA Saudi Arabia OTCC-1 2022 | 2-3-1-13 2-4-1-12 |
| EMEA Saudi Arabia SACS-002 2022 | VII.B.TPC-76 |
APAC (7)
| Framework | Mapping Values |
|---|---|
| APAC Australia CCM 2026 | PRO-18 PRO-09 |
| APAC Australia ISM June 2026 | ISM-0611 ISM-0612 ISM-0613 ISM-0616 ISM-0619 ISM-0622 ISM-0628 ISM-0629 ISM-0631 ISM-0634 ISM-0637 ISM-0639 ISM-1037 ISM-1192 ISM-1284 ISM-1286 ISM-1287 ISM-1288 ISM-1289 ISM-1293 ISM-1389 ISM-1427 ISM-1520 ISM-1521 ISM-1522 ISM-1528 |
| APAC Malaysia RMiT 2025 | A5-A4(a) |
| APAC New Zealand NZISM 3.9 | 19.1.10.C.01 19.1.11.C.01 19.1.11.C.02 19.1.12.C.01 19.1.13.C.01 19.1.14.C.01 19.1.14.C.02 19.1.15.C.01 19.1.16.C.01 19.1.16.C.02 19.1.17.C.01 19.1.17.C.02 19.1.18.C.01 19.1.18.C.02 19.1.19.C.01 19.1.19.C.02 19.1.19.C.03 19.1.19.C.04 19.1.19.C.05 19.1.20.C.01 19.1.20.C.02 19.1.20.C.03 19.1.21.C.01 19.1.22.C.01 19.1.22.C.02 19.1.22.C.03 19.1.23.C.01 19.3.8.C.01 19.3.8.C.02 19.3.8.C.03 19.3.8.C.04 19.3.9.C.01 19.3.9.C.02 19.3.9.C.03 19.4.4.C.01 19.4.5.C.01 19.4.5.C.02 19.4.5.C.03 19.4.6.C.01 19.5.24.C.01 19.5.24.C.02 19.5.24.C.03 19.5.24.C.04 19.5.24.C.05 19.5.24.C.06 19.5.24.C.07 19.5.24.C.08 19.5.25.C.01 19.5.26.C.01 19.5.26.C.02 19.5.26.C.03 19.5.26.C.04 19.5.26.C.05 19.5.26.C.06 19.5.26.C.07 19.5.26.C.08 19.5.26.C.09 19.5.26.C.10 19.5.26.C.11 19.5.26.C.12 19.5.27.C.01 19.5.27.C.02 19.5.27.C.03 19.5.27.C.04 19.5.27.C.05 19.5.27.C.06 19.5.28.C.01 19.5.28.C.02 19.5.28.C.03 19.5.28.C.04 19.5.28.C.05 19.5.28.C.06 19.5.28.C.07 19.5.29.C.01 21.3.5.C.01 21.3.5.C.02 21.3.6.C.01 |
| APAC Singapore CCOP CII 2026 | 5.5.3(a) 5.6.2 5.6.2(a) 10.2.1 10.4.1(a) 12.4.2 |
| APAC Singapore Cyber Hygiene Practice 2019 | 4.4 |
| APAC Singapore MAS TRM 2021 | 11.2.1 |
Americas (1)
| Framework | Mapping Values |
|---|---|
| Americas Canada ITSP-10-171 2025 | 03.01.12.A 03.01.18.A 03.13.01.A 03.13.01.B 03.13.01.C |
Capability Maturity Model
Level 0 — Not Performed
Practices are non-existent, based on the inability to demonstrate an implemented and operational capability. A reasonable person would conclude the control is not being performed.
Level 1 — Performed Informally
SCR-CMM Level 1 criteria definitions are not available for this control: ▪ A reasonable person would conclude this control requires a structured process. ▪ At this level of maturity, the "ad hoc" nature of performing a capability informally would indicate the intent of the control is not met due to a lack of consistency and formality.
Level 2 — Planned & Tracked
Network Security (NET) capabilities are requirements-driven, but are not standardized across the entity (e.g., local/regional level consistency). Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Policies and standards associated with NET domain capabilities are formally documented and centrally-managed by the entity. ▪ Standardized Operating Procedures (SOP) associated with NET domain capabilities are documented and maintained by process owners. ▪ IT and/or cybersecurity personnel work with business stakeholders and process owners to appropriately scope and reasonably implement cybersecurity and data protection controls associated with NET domain capabilities to address applicable statutory, regulatory and/or contractual requirements for Technology Assets, Applications, Services and/or Data (TAASD). ▪ Network security-related controls are primarily administrative and preventative in nature (e.g., policies, standards and procedures & guidelines). ▪ Network security management may be a defined function (e.g., team or department) or assigned as an additional duty to existing IT and/or cybersecurity personnel. ▪ IT personnel define secure networking practices to protect the Confidentiality, Integrity, Availability and Safety (CIAS) of the organization's TAASD. ▪ Secure Baseline Configurations (SBC) enforce the principles of least privileges and least functionality for boundary protection technologies. ▪ SBC enforce network activity monitoring and control communications at the external network boundary and at key internal boundaries within the network.
Level 3 — Well Defined
Network Security (NET) capabilities are standardized across the entity for applicability to People, Processes, Technologies, Data and/or Facilities (PPTDF) to ensure consistency for Technology Assets, Applications, Services and/or Data (TAASD). Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Policies and standards associated with NET domain capabilities are formally documented and centrally-managed by the entity's Governance, Risk & Compliance (GRC) team, or similar function. ▪ Standardized Operating Procedures (SOP) associated with NET domain capabilities are well-documented and kept current by process owners. ▪ A network security management team, or similar function, is appropriately staffed and supported to implement and maintain NET domain capabilities. ▪ Technology is leveraged to enhance the efficiency and accuracy of network security operations (e.g., network management solution and log aggregator). ▪ The entity's Governance, Risk & Compliance (GRC) team, or similar function, works with business stakeholders and process owners to appropriately scope and reasonably implement cybersecurity and data protection controls associated with NET domain capabilities to address Minimum Compliance Requirements (MCR) (e.g., applicable statutory, regulatory and/or contractual requirements) and Discretionary Security Requirements (DSR) (e.g., entity-required controls). ▪ Secure Baseline Configurations (SBC) enforce the principles of least privileges and least functionality for boundary protection technologies. ▪ An implemented and operational capability exists to monitor and control communications at the external network boundary and at key internal boundaries within the network.
Level 4 — Quantitatively Controlled
Utilize SCR-CMM Level 3 criteria definitions: ▪ There are no defined Level 4 criteria, since it is reasonable to assume a quantitatively-controlled process is not necessary to operationalize this control. ▪ While it may be possible to develop “metrics-driven” capabilities for this control, the criteria would be organization-specific to define.
Level 5 — Continuously Improving
Utilize SCR-CMM Level 3 or Level 4 (if available) criteria definitions: ▪ There are no defined Level 5 criteria, since it is reasonable to assume a continuously-improving process is not necessary to operationalize this control. ▪ Level 5 capabilities should be considered “world-class” where the control builds on Level 4 capabilities, but are continuously improving through Artificial Intelligence (AI) and/or Machine Learning (ML) technologies. ▪ While it may be possible to develop responsive capabilities for this control through the use of AI and/or ML technologies, the criteria would be organization-specific to define.
Assessment Objectives
- NET-03_A01 the external system boundary is defined.
- NET-03_A02 key internal system boundaries are defined.
- NET-03_A03 communications are protected at the external system boundary.
- NET-03_A04 communications are protected at key internal boundaries.
- NET-03_A05 communications are monitored at the external system boundary.
- NET-03_A06 communications are controlled at the external system boundary.
- NET-03_A07 communications are monitored at key internal boundaries.
- NET-03_A08 communications are controlled at key internal boundaries.
- NET-03_A09 subnetworks for publicly accessible system components are selected per organization-defined values separated from internal organizational networks.
- NET-03_A10 external networks or systems are only connected to through managed interfaces consisting of boundary protection devices arranged in accordance with an organizational cybersecurity / data privacy architecture.
- NET-03_A11 outgoing communications traffic posing a threat to external systems is detected.
- NET-03_A12 outgoing communications traffic posing a threat to external systems is denied.
- NET-03_A13 the identity of internal users associated with denied communications is audited.
- NET-03_A14 authorized sources of incoming communications to be routed are defined.
- NET-03_A15 authorized destinations to which incoming communications from authorized sources may be routed are defined.
- NET-03_A16 only incoming communications from authorized sources are allowed to be routed to authorized destinations.
- NET-03_A17 one or more of the following is/are selected: physical isolation techniques. logical isolation techniques.
- NET-03_A18 physical isolation techniques are defined.
- NET-03_A19 logical isolation techniques are defined.
- NET-03_A20 physical isolation techniques and/or organization-defined logical isolation techniques are employed in organizational systems and system components.
- NET-03_A21 connection requirements are established for mobile devices.
- NET-03_A22 external system connections are only made through managed interfaces that consist of boundary protection devices arranged in accordance with an organizational security architecture.
- NET-03_A23 communications at external managed interfaces to the system are controlled.
- NET-03_A24 communications at key internal managed interfaces within the system are controlled.
Evidence Requirements
- E-NET-07 External System Accessibility
-
Documented evidence of a list of Technology Assets, Applications and/or Services (TAAS) accessible from third-party entities.
Network Security - E-NET-08 Internal Boundaries
-
Documented evidence of key internal boundaries.
Network Security - E-NET-09 Network Access Control Points
-
Documented evidence of network access control points.
Network Security
Technology Recommendations
Micro/Small
- Firewall as boundary protection device
Small
- Business-grade firewall (e.g., Cisco Meraki, pfSense)
- DMZ for public-facing services
Medium
- NGFW boundary protection
- DMZ architecture
- IDS/IPS at perimeter
Large
- Enterprise NGFW with IPS
- DMZ design
- Network segmentation
- Perimeter monitoring
Enterprise
- Enterprise perimeter security
- NGFW, IPS, DMZ
- Zero-trust perimeter
- Continuous boundary monitoring