Which NAC is best for multi-vendor network environments?

Aruba ClearPass Policy Manager consistently outperforms in multi-vendor scenarios. Its extensive RADIUS dictionary support and OnConnect framework allow for seamless integration with switches and WLAN controllers from Cisco, Juniper, Extreme, HP, and others. ClearPass Exchange provides numerous partner integrations out-of-the-box, reducing custom development.

What is the most cost-effective NAC solution for large enterprises?

For enterprises primarily standardized on Fortinet, FortiNAC generally offers the lowest TCO, especially when leveraging existing FortiGate and FortiSwitch infrastructure. However, for genuinely vendor-neutral environments, the overall TCO can vary significantly based on licensing model, required features (e.g., posture, advanced IoT), and hardware versus VM deployment strategies.

Which NAC offers the best IoT/OT device visibility and enforcement?

Aruba ClearPass, especially when combined with Aruba Device Insight, provides a strong solution for IoT/OT through its granular profiling and cloud-native analytics. FortiNAC also excels with its native agentless discovery and Fortinet Fabric integration for enforcement. Cisco ISE requires integration with Cisco Cyber Vision for comparable depth in industrial environments.

How do these NACs handle Zero Trust Network Access (ZTNA)?

All three platforms are foundational to ZTNA. Cisco ISE uses TrustSec SGTs and pxGrid to enforce identity-based microsegmentation. Aruba ClearPass leverages device context from profiling and MDM integrations to dynamically apply firewall policies. FortiNAC uses its Security Fabric integration to enforce granular policies on FortiGates. The choice depends on existing network and security architectures.

Is agent-based or agentless posture assessment preferred?

Agent-based posture (Cisco AnyConnect, Aruba OnGuard, FortiClient) provides the most detailed and real-time endpoint compliance checks. Agentless methods rely on network insights or MDM integration, offering less granular control but essential for devices that cannot run agents (e.g., printers, IP cameras, OT devices). A hybrid approach is often required in complex environments.

What level of effort is required to deploy and maintain these NAC solutions?

Cisco ISE deployments are typically the most complex, requiring deep understanding of Policy Sets, TrustSec, pxGrid, and distributed architecture. Aruba ClearPass offers a more intuitive policy engine but still requires significant effort for multi-vendor integrations and advanced features. FortiNAC can be simpler to deploy within a Fortinet-centric environment due to unified management, but still demands expertise in network topology and device profiling.

Cisco ISE vs Aruba ClearPass vs FortiNAC: 2026 Enterprise NAC Comparison

Choosing a Network Access Control (NAC) platform in 2026 is less about basic .1X/MAB and more about Zero Trust orchestration, IoT/OT segmentation, and supply chain integrity. This analysis evaluates Cisco Identity Services Engine (ISE) 3.4, Aruba ClearPass Policy Manager (CPPM) 6.13, and Fortinet FortiNAC 9.5. We cut through marketing to expose architectural strengths, integration depth, and total cost of ownership (TCO) for deployments scaling to 100,000 endpoints.

Core Architecture & Scalability

Cisco ISE operates as a distributed system with Administration, Policy Service, and Monitoring persona nodes. For 100,000 endpoints, a deployment would typically involve two primary PANs (Policy Administration Nodes) in an active/standby pair, four to eight PSNs (Policy Service Nodes) for RADIUS/TACACS+ and posture, and two MnTs (Monitoring and Troubleshooting nodes). PSNs require robust hardware; a Cisco SNS-3715 appliance or equivalent VM for ~25,000 concurrent sessions is typical. Latency between PSNs and endpoints is critical for dot1x authentication, dictating distribution strategy. Cisco's architecture leverages PXGrid for real-time contextual sharing with other security platforms, including Cisco Secure Firewall (FTD) and Cisco Secure Endpoint (formerly AMP for Endpoints).

Aruba ClearPass Policy Manager employs a similar distributed model: Publishers, Subscribers, and Log Collectors. The Publisher (primary) handles configuration, while Subscribers (secondary) perform authentication and policy enforcement. For 100,000 endpoints, a Publisher/Subscriber cluster would likely consist of two Publishers (active/standby) and eight to twelve Subscribers, potentially using ClearPass C3000V virtual appliances scaled to handle 25,000-50,000 concurrent sessions each. ClearPass excels at multi-vendor network integration using OnConnect and its robust dictionary support. Device Insight adds a dedicated, cloud-native IoT visibility layer, which effectively offloads deep profiling from the core CPPM nodes.

FortiNAC 9.5 distinguishes itself with an Agent (application policy enforcement), Manager (centralized configuration & reporting), and Data Collector architecture. For large-scale deployments, multiple Managers can be deployed for redundancy, with numerous Agents geographically distributed to handle local authentication load. A FortiNAC-VM64-Mgr can handle up to 25,000 devices, while FortiNAC-VM64-Agent supports similar scale. FortiNAC leverages FortiGates as inline enforcement points and integrates tightly with the Fortinet Security Fabric, sharing threat intelligence and policy with FortiAnalyzer and FortiManager. Its agentless discovery relies heavily on SNMP, NetFlow/IPFIX, and passive techniques for accurate asset identification, especially crucial for OT/IoT environments lacking agent support.

Authentication and Authorization Services (.1X, MAB, TACACS+)

Cisco ISE's strength lies in its Policy Sets, which offer granular control flow for authentication and authorization. It natively supports dot1x, MAB, and has deep integration with Active Directory via AD Join. TACACS+ for network device administration (e.g., Catalyst 9300X-48HXN, FortiGate 1800F, PA-5440) is robust, leveraging command sets, shell profiles, and attribute filters for precise RBAC. TrustSec Security Group Tags (SGTs) are central to Cisco's microsegmentation strategy, allowing network enforcement points (switches, routers, firewalls) to enforce policy based on user/device identity, not just IP address. This simplifies ACL management significantly across large campuses.

Aruba ClearPass excels in heterogeneous environments due to its extensive support for RADIUS dictionaries and vendor-specific attributes (VSAs). Its service templates simplify configuration for dot1x and MAB across various network vendors. ClearPass also provides robust TACACS+ services, with an intuitive policy engine for device administration and command authorization. Its insight into device types from onboarding, guest, and profiling systems allows for highly contextual authorization policies. ClearPass Guest is a mature, feature-rich module for self-service or sponsored guest access, including social logins and captive portal customization.

FortiNAC provides comprehensive dot1x and MAB support, with a strong focus on device visibility before authentication. Its profiling engine, using techniques like DHCP fingerprinting, NMAP scans, SNMP, and HTTP probes, attempts to identify devices accurately first. This allows for policies such as quarantining unknown devices or assigning them to a limited guest VLAN until further identification or registration. TACACS+ support is functional but leans heavily into the Fortinet ecosystem for integration attributes. While it supports generic network devices, its deepest integration is with FortiGate and FortiSwitch for command authorization and auditing.

IoT/OT Device Profiling & Segmentation

Cisco ISE leverages its profiling services, which analyze DHCP, HTTP, DNS, NetFlow, and SNMP data to identify devices. For deeper IoT/OT visibility, Cisco Cyber Vision (formerly SOTI) integrates with ISE via pxGrid, providing specialized industrial protocol analysis and asset inventory that ISE alone cannot. This allows for fine-grained SGT assignment and enforcement on network devices. For truly agentless environments, the integration with CCV or third-party solutions is mandatory, as ISE's native profiling, while good for IT assets, can be less precise for obscure ICS/OT protocols.

Aruba's Device Insight complements ClearPass by providing a cloud-native, AI-powered discovery and profiling engine specifically designed for IoT, medical, and OT devices. It uses passive and active techniques, including packet inspection, without requiring agents. This offloads the heavy lifting of profiling from the ClearPass Subscribers, allowing CPPM to focus on policy enforcement. ClearPass OnConnect integrates with switches to dynamically assign VLANs or firewall rules based on Device Insight's classification, effectively segmenting these devices. This two-pronged approach is effective for large and complex IoT deployments.

FortiNAC shines in its agentless discovery and robust profiling capabilities out-of-the-box. It employs a multi-faceted approach, including sniffer collection, NetFlow/IPFIX analysis, and direct API integrations with common IoT platforms. This allows for precise identification of devices that cannot run agents. Once identified, FortiNAC assigns dynamic policies that can be enforced via FortiGate firewalls or FortiSwitch devices, pushing devices into specific VLANs or applying microsegmentation rules. This native capability significantly reduces deployment complexity when dealing with large numbers of unmanaged IoT/OT assets.

Posture Assessment & Endpoint Compliance

Cisco ISE offers extensive posture assessment capabilities through its AnyConnect Network Access Manager (NAM) agent, which can check for antivirus status, patch levels, running processes, registry keys, and more. For agentless scenarios, it can perform basic OS checks. Integration with MDM solutions (e.g., Microsoft Intune, VMware Workspace ONE) via pxGrid allows ISE to retrieve device compliance status directly from MDM. Compliance failures can result in dynamic policy changes, like moving a non-compliant device to a remediation VLAN or applying a restrictive Access Control List (ACL) via TrustSec.

Aruba ClearPass OnGuard is a feature-rich dissolvable or persistent agent for endpoint posture checks, supporting Windows, macOS, Linux, and mobile operating systems. It assesses antivirus, EDR status (e.g., CrowdStrike Falcon, SentinelOne), patch compliance, disk encryption, and presence of forbidden applications. ClearPass also integrates with various MDM platforms (e.g., Jamf, Microsoft Intune) and EDR solutions via API for advanced compliance checks without an agent on the endpoint itself. Non-compliant devices can be automatically quarantined or given restricted access based on pre-defined policies.

FortiNAC's posture assessment, FortiClient, is tightly integrated into the Fortinet Security Fabric. FortiClient offers a comprehensive set of posture checks for Windows, macOS, and Linux endpoints, including application presence, system health, file changes, and service status. For devices without FortiClient, FortiNAC can leverage host scanning techniques like NMAP or WMI to infer compliance, and also integrates with MDM platforms. FortiNAC can trigger FortiGate policies to isolate or remediate non-compliant devices, extending the enforcement domain beyond just the access layer.

Integration with Security Ecosystem (NGFW, EDR, MDM)

Cisco ISE's pxGrid framework is its crown jewel for ecosystem integration. It allows real-time context sharing with Cisco Secure products (Firewall, Endpoint, Cloud Mail) and over 60 third-party vendors. This enables Advanced Threat Protection (ATP) use cases where, for example, a threat detection on a workstation by Cisco Secure Endpoint can trigger ISE to quarantine that device via an SGT change on a Catalyst 9k switch or FTD. MDM integration for mobile device posture and ownership information is common, enabling Zero Trust segmentation policies based on device trust.

Aruba ClearPass leverages its API-first approach and vendor-agnostic design for extensive integration. It has out-of-the-box connectors for leading NGFWs (Palo Alto PA-5440, Check Point, FortiGate), EDR solutions (CrowdStrike, SentinelOne), and MDM platforms (Intune, Workspace ONE). ClearPass Exchange is a key differentiator, providing a marketplace for pre-built integrations and extensions. Policy updates can be pushed to firewalls for dynamic rule enforcement based on ClearPass's identity context, effectively extending microsegmentation to the perimeter or data center.

FortiNAC's strength lies in its tight integration within the Fortinet Security Fabric. It can share device context with FortiGate (for firewall policy enforcement), FortiAnalyzer (for logging and analysis), FortiManager (for centralized management), and FortiClient EMS (for endpoint management). This allows for a unified policy enforcement across the network and security layers. While it supports generic RADIUS/TACACS+ for non-Fortinet devices, its deepest, most effective integrations are within the Fortinet ecosystem, enabling simplified orchestration of security policies from endpoint to firewall.

Deployment & Licensing Complexity, TCO

Cisco ISE licensing can be complex, involving Base, Plus, Apex, and Advantage tiers, sometimes with added Device Admin licenses. It's perpetual, with an annual support contract. For a 20,000 endpoint deployment, expect a mix of Plus (for advanced profiling/guest), Apex (for MDM/EPP integration, posture), and maybe Advantage for TrustSec. A typical 20,000-endpoint deployment (5k concurrent) might involve 3-4 PSNs, a pair of PANs, and a pair of MnTs. List price for perpetual licenses alone for 20,000 endpoints with Plus/Apex features could range from $300,000 to $600,000 for software, plus SNS hardware (~$80,000-$150,000) and 3 years SMARTnet (~$100,000-$200,000). Total 3-year TCO could approach $1M-$1.5M, depending heavily on features and negotiation.

Aruba ClearPass licensing is subscriber-based (Entry, Access, Policy Manager, Guest, OnGuard, Device Insight) and often sold as an annual subscription model or perpetual with separate services. For 20,000 endpoints (5k concurrent), a mix of Policy Manager, OnGuard, and Device Insight licenses would be required. An indicative list price for 20,000 Policy Manager licenses, 5,000 OnGuard, and 20,000 Device Insight, with 3 years of subscription, might be in the $400,000-$700,000 range. Hardware (C3000V equivalent VMs) is usually customer-provided, reducing upfront CapEx but shifting to OpEx for hypervisor resources. Total 3-year TCO for a 20k enterprise might be around $800,000-$1.2M.

FortiNAC licensing is simpler, typically device-based (Endpoint, IoT, Guest) and feature-based (Basic, Advanced, Premium). It can be perpetual or subscription. A 20,000-endpoint deployment with Advanced features would require licences for the manager and agents, plus endpoint/IoT device licenses. For 20,000 devices, FortiNAC-VM64-Mgr and two FortiNAC-VM64-Agent appliances would be deployed. List price for 20,000 devices with Advanced features plus 3 years of support could be $250,000-$450,000. Hardware is usually VM-based. Total 3-year TCO could hover around $600,000-$900,000, making it generally the lowest TCO option for Fortinet-centric environments.

TCO Comparison (Indicative List Price for 20,000 Endpoints, 3-Year Total)

Platform	Software/Subscription Licenses (20k Endpoints)	Hardware/VM Costs (Estimated)	Total Indicative 3-Year TCO	Key Differentiator
Cisco ISE	$300,000 - $600,000 (Plus/Apex)	$80,000 - $150,000 (SNS-3715 equivalent)	$1,000,000 - $1,500,000	TrustSec/SGTs, pxGrid Ecosystem
Aruba ClearPass	$400,000 - $700,000 (PM, OG, DI)	Customer-provided VMs ($50,000 - $100,000 equivalent)	$800,000 - $1,200,000	Multi-vendor support, Device Insight
FortiNAC	$250,000 - $450,000 (Advanced)	Customer-provided VMs ($30,000 - $60,000 equivalent)	$600,000 - $900,000	Fortinet Fabric Integration, Agentless DNA

Verdict

Cisco ISE wins for organizations deeply invested in the Cisco ecosystem, especially Catalyst 9000 switches and Cisco Secure products. Its TrustSec SGT-based microsegmentation and pxGrid integrations provide unparalleled orchestration capabilities for a truly Zero Trust architecture, though at a premium cost and significant configuration overhead. If your network is 80%+ Cisco and you need deep, identity-driven segmentation that scales, ISE remains a dominant, albeit complex, player. TrustSec still provides the most elegant solution for layer 2/3 segmentation at scale without relying solely on VLANs.

Aruba ClearPass is the clear winner for heterogeneous network environments that require vendor-agnostic policy enforcement. Its robust profiling, comprehensive guest access, and Device Insight for IoT/OT provide a flexible and powerful solution without forcing a vendor lock-in. For enterprises with a mix of access layer hardware (e.g., Extreme, Juniper, HP, Cisco) and a strong need for IoT visibility, ClearPass offers the best balance of features, integration, and reasonable TCO. Its API-first approach ensures adaptability to future security tools.

Fortinet FortiNAC stands out for organizations committed to the Fortinet Security Fabric. Its deep integration with FortiGate firewalls, FortiSwitch, and FortiClient simplifies management and extends policy enforcement seamlessly across the network. For environments with a large contingent of unmanaged IoT/OT devices and a primary goal of consolidating security vendors under Fortinet, FortiNAC offers the most cost-effective and highly integrated solution for discovery, profiling, and segmentation. Its agentless capabilities are a strong selling point for industrial and embedded systems.