Network Access Control for Identity-First, Posture-Aware Connectivity
Network Access Control (NAC) decides who/what may connect to your wired, wireless, and VPN networks—only if identity is proven and the device is healthy.
SolveForce designs NAC so every port and SSID becomes Zero-Trust-aware: 802.1X EAP-TLS by default, posture checks (EDR/UEM), dynamic VLAN/ACL/SGT assignment, quarantine on failure, and auditable logs to SIEM/SOAR.
Where NAC fits in the SolveForce model:
🔒 Security (Semantics) → Cybersecurity • 🔑 Identity → IAM / SSO / MFA
🖥️ Device trust → MDM / UEM • 🛡️ Endpoint → EDR / MDR / XDR
🔐 Access → ZTNA / SASE • 🧭 Routing/SD-WAN → SD-WAN
🪪 Certificates/Keys → PKI • Key Management / HSM • 🔐 Encryption
🖧 Fabric → Networks & Data Centers • 🌐 Connectivity • 📊 SIEM / SOAR
🎯 Outcomes (What strong NAC delivers)
- Least-privilege by default — every port/SSID enforces identity and device posture before access.
- Automated segmentation — dynamic VLANs/ACLs/SGTs (Scalable Group Tags / TrustSec-style) based on who/what/where.
- Quarantine & coaching — non-compliant devices land in remediation; users get clear steps to fix.
- IoT/OT safety — headless devices profiled and isolated; per-function micro-segmentation.
- Audit-grade evidence — who/what/when/where + policy decision + posture status shipped to SIEM/SOAR.
🧭 Scope (Wired, Wireless, VPN, Guest, IoT/OT)
- Wired access (802.1X on edge switches) — EAP-TLS for corp devices; MAC Authentication Bypass (MAB) only for vetted exceptions.
- Wireless (WPA2/WPA3-Enterprise) — EAP-TLS + posture; dynamic roles for staff/guest/contractor/IoT SSIDs.
- VPN — identity + device posture at tunnel start; dynamic group policies; short re-auth timers.
- Guest/Contractor — sponsor portal / captive portal with time-boxed credentials; bandwidth and app restrictions.
- IoT/OT — cameras, printers, scanners, POS, sensors: profile → tag → isolate; DHCP/LLDP/OUI fingerprinting + device posture where possible.
🧱 Building Blocks (Spelled out)
- 802.1X / EAP-TLS — certificate-based port/SSID authentication; strongest, phishing-resistant. → PKI
- RADIUS / Change of Authorization (CoA) — real-time authorization and re-auth; change device policy on the fly.
- Posture assessment — check EDR health, disk encryption, OS level, jailbreak/root, UEM enrollment. → MDM / UEM • EDR / MDR / XDR
- Dynamic policies — VLAN/ACL/SGT assignment per role, device type, and risk.
- Profiling — LLDP/CDP, DHCP fingerprints, OUI, traffic heuristics for headless IoT/OT.
- Guest services — sponsor approval, SMS/e-mail vouchers, captive portal, legal banner.
- Logging & evidence — decision logs (authN/authZ), posture, CoA events → SIEM/SOAR. → SIEM / SOAR
🔐 Policy Model (Identity → Device → App → Data → Context)
A NAC decision evaluates five lenses before granting network access:
- Identity — user/service group via IAM/SSO/MFA; separate admin identities. → IAM / SSO / MFA
- Device posture — UEM/EDR health, OS min, encryption on, certificate present. → MDM / UEM • EDR / MDR / XDR
- Application needs — map to SGT/VLAN/ACL sets; minimal east-west access.
- Data sensitivity — DLP labels narrow access to restricted zones; read-only where needed. → DLP
- Context — site/geo/ASN, time window, change ticket, session risk.
Outcome: allow (role VLAN/SGT) → step-up (MFA or posture remediation) → isolate (quarantine VLAN/guest) → deny.
🧰 Controls (Concrete & enforceable)
- Certificates everywhere — 802.1X EAP-TLS for corp devices; device/user certs auto-enrolled via MDM/PKI. → PKI
- Dynamic segmentation — assign VLAN/ACL/SGT per role; push CoA on posture change.
- Quarantine VLAN — walled garden + remediation portal; redirect until compliant.
- Command & visibility — RADIUS accounting, netflow/IPFIX, DHCP/DNS logs to SIEM.
- Headless/legacy (MAB) — static MAC lists only as last resort; tag as Restricted; watch for spoof; rotate to certs asap.
- Guest access — time-boxed creds, bandwidth caps, DNS filtering, L7 threat block via SASE. → SASE
- OT/IoT — profile, tag minimal policies, deny east-west; separate mgmt plane; monitor with NDR. → NDR
☁️ & WAN Integrations (Real-world interlock)
- SD-WAN — honor NAC tags (SGT/role) across the fabric; app-aware steering per role/SLO. → SD-WAN
- ZTNA/SASE — NAC decides who gets a port; ZTNA/SASE decides which app per session. → ZTNA • SASE
- PKI/KMS/HSM — issue/rotate device certs; keep private keys non-exportable. → Key Management / HSM
- SIEM/SOAR — contain via NAC: CoA, quarantine VLAN, or port-shut on incident; all actions auditable. → SIEM / SOAR
📐 SLO Guardrails (Experience you can measure)
| Metric (p95) | Target (Recommended) | Notes |
|---|---|---|
| 802.1X auth time (wired/wifi) | ≤ 1–3 s / ≤ 2–5 s | Cached EAP-TLS + fast RADIUS |
| Posture eval to CoA | ≤ 30–90 s | Health change → policy change |
| Guest onboarding | ≤ 60–120 s | Sponsor approval + captive |
| False reject rate | ≤ 1–2% | Tune cert chains & supplicants |
| Availability (RADIUS/NAC core) | ≥ 99.99% | Dual NAC nodes + site HA |
| Evidence completeness | 100% | AuthN/Z + posture + CoA logs |
🛠️ Implementation Blueprint (No-surprise rollout)
- Inventory — switches/APs/VPN concentrators, sites/ports, SSIDs, device types (corp/BYOD/IoT/OT).
- Identity & PKI — pick identity sources, define groups/roles, plan EAP-TLS cert issuance/rotation. → IAM / SSO / MFA • PKI
- Policy design — role matrix → VLAN/ACL/SGT; quarantine & guest policies; MAB exceptions register.
- Posture baselines — UEM/EDR min versions, encryption on, firewall on, jailbreak/root blocked. → MDM / UEM • EDR / MDR / XDR
- Pilot rings — a floor/SSID first; enable 802.1X with fail-open (brief), then fail-closed; measure SLOs.
- Automations — remediation portal, self-service cert fix, CoA triggers; change windows documented.
- Logging — RADIUS accounting, DHCP/DNS, netflow to SIEM; SOAR playbooks for quarantine. → SIEM / SOAR
- Go broad — campus → branches → datacenter mgmt VLANs; retire MAB; quarterly posture raises.
🧩 Policy Matrix (example sketch)
| Role/Type | Auth | Posture | Network Result |
|---|---|---|---|
| Corp-Laptop | EAP-TLS (cert) | EDR+UEM healthy | Corp VLAN + SGT=Staff; full intranet |
| Admin-Workstation | EAP-TLS | EDR healthy | Admin VLAN; mgmt ACL; session recording |
| BYOD | Portal + SSO | Work profile ok | Internet-only; ZTNA to private apps |
| Contractor | EAP-TLS/Portal | EDR/UEM (vendor) | Restricted VLAN; allow only needed apps |
| Printer/Camera | MAB (temp) | N/A (profiled) | IoT VLAN; block east-west; mgmt only |
| Non-compliant | Any | Fails posture | Quarantine VLAN + remediation portal |
🧾 Compliance Mapping (Examples)
- PCI DSS — segment cardholder data environment; strong auth at ports; logging.
- HIPAA — device accountability; isolation of PHI networks; audit trails.
- ISO 27001 — A.9 access control; A.12 operations; A.13 network security.
- NIST 800-53/171 — AC-17/18, IA-2, CM-7 (least privilege, device auth, configuration).
- CMMC — controlled access & auditing for CUI zones.
All NAC decisions stream to SIEM with immutable evidence and case linkage. → SIEM / SOAR
✅ Pre-Engagement Checklist
- 🔐 Identity sources (IdP/AD), group/role taxonomy, MFA rules.
- 🪪 PKI readiness (device/user certs), auto-enrollment via UEM. → PKI • MDM / UEM
- 🧩 Switch/AP/VPN capabilities (802.1X, CoA, SGT/TrustSec-like tags).
- 🧠 Posture baseline (EDR/UEM, OS minimums, encryption).
- 🗺️ Policy matrix (roles → VLAN/ACL/SGT); quarantine design.
- 🧪 Pilot plan (sites/SSIDs), rollback strategy, SLO targets.
- 📊 Logging destinations & retention (SIEM), SOAR playbooks for quarantine.
🔄 Where NAC Fits (Recursive View)
1) Grammar — access rides Connectivity & the Networks & Data Centers fabric.
2) Syntax — auth flows and segmentation patterns in Cloud & WAN.
3) Semantics — Cybersecurity preserves truth; NAC proves device/identity before entry.
4) Pragmatics — SolveForce AI spots anomalies, predicts drift, and suggests auto-quarantine.
5) Foundation — consistent terms via Primacy of Language.
6) Map — indexed in the SolveForce Codex & Knowledge Hub.
📞 Deploy NAC That’s Identity-First & Audit-Ready
Related pages:
Cybersecurity • IAM / SSO / MFA • MDM / UEM • EDR / MDR / XDR • ZTNA • SASE • SD-WAN • SIEM / SOAR • Networks & Data Centers • Knowledge Hub