ClearPass vs Cisco ISE: NAC Platform Comparison

Both ClearPass Policy Manager and Cisco Identity Services Engine answer the same question — may this endpoint use this port, and in what role — but they enforce it through different mechanisms and fit different estates. The decision usually comes down to what your switches are, how much profiling accuracy you need, and how far you want to go beyond simple VLAN assignment. This comparison lays out the policy model, the enforcement toolkit, and the mixed-vendor reality that neither vendor's datasheet covers well.

Policy model

Enforcement depth

Both platforms assign a VLAN or an ACL on the port after authentication:

# 802.1X on the switch side (ArubaOS-CX shown)
aaa authentication port-access dot1x authenticator
interface 1/1/1
   aaa authentication port-access dot1x authenticator
! RADIUS attributes returned by the NAC platform decide the role

# Cisco IOS-XE equivalent
interface GigabitEthernet1/0/1
 authentication port-control auto
 dot1x pae authenticator
 mab
 authentication event fail action authorize vlan 999

Beyond VLAN/ACL, the platforms diverge. ClearPass's Downloadable User Roles push a complete role definition (ACL, QoS, session parameters) to Aruba switches and controllers, so policy changes do not require a switch template rewrite. ISE's Security Group Tags, combined with TrustSec-capable hardware, carry a tag inside the frame and enforce it anywhere on the path — powerful, but it assumes a refresh cycle that supports it end to end.

Profiling accuracy and where it matters

# Typical profiling inputs both platforms consume
- DHCP fingerprint (option 55 parameter request list)
- MAC OUI
- CDP/LLDP neighbour data
- NetBIOS / mDNS / DHCP hostname
- HTTP user-agent seen through a portal
- Agent-based posture (OnGuard / Cisco Secure Client)

Profiling accuracy determines how often a device lands in the wrong role. Agentless profiling is good enough for IoT and printers in most networks; anything that must be posture-checked (patch level, disk encryption, antivirus) needs an agent, which shifts the conversation to endpoint management rather than network design.

Deployment realities

• Alert-only first. Run both platforms in monitor mode for at least two weeks; the first week of enforcement almost always locks out legitimate devices that were never profiled correctly.
• Plan a fail-open path. Decide per port what happens when the RADIUS server is unreachable. authentication event server dead action authorize vlan is safer than shutting the port, but on guest-facing ports it may be the wrong trade-off.
• Licensing is per endpoint. IoT growth, not user growth, drives renewals — model it before the pilot.
• Mixed estates favour ClearPass for multi-vendor enforcement; Cisco-centric estates favour ISE for TrustSec and integration with the rest of the Cisco ecosystem.

Related reading: WPA3-Enterprise 802.1X wireless RADIUS configuration, FreeRADIUS EAP-TLS for wired 802.1X on Cisco switches, and ArubaOS-CX 802.1X port access with RADIUS and MAB roles.

原文链接：https://arubanetworking.hpe.com/techdocs/NAC/clearpass/platform/wired-policy-enforcement