Gartner Research

Architectural Alternatives for Enforcing Network Access Control Requirements

Published: 29 March 2012

ID: G00227091

Analyst(s): Eric Maiwald


Network access control (NAC) is about just that: control. Properly architected, NAC can assist with control over endpoints on the network (guest access is a primary driver for implementing a NAC solution). But the cost of implementing NAC properly is its impact on the fundamental network architecture. This assessment analyzes both the effect NAC will have on a network and the strengths and weaknesses of the various NAC enforcement approaches available today.

Table Of Contents

Summary of Findings


  • Drivers for NAC
  • Components of a NAC System
  • Architectural Approaches
    • Preconnect vs. Postconnect
    • Policy
    • Endpoint Baseline Configuration Checks
  • Issues and Concerns
    • Exceptions
    • Impact on Network Architecture
  • Examples of Approaches in the Real World
    • Remote Access
    • WLAN Access
  • Gartner Definitions


  • Treat NAC as an Architecture and Not as a Product
  • Address the Biggest Risk Areas First
  • Look Beyond Vendor Marketing and Determine the Architectures Actually Supported
  • Understand the Business Issues Involved With NAC

The Details

  • PEP: Switch (or AP)
    • PDP: RADIUS Server (802.1X)
    • PDP: OOB Device Monitoring Network Traffic
    • PDP: OOB Device Queried Before Connection
  • PEP: In-Line Appliance
  • PEP: OOB Device
  • PEP: DHCP Server
  • PEP: Endpoint Agent
    • PDP: Destination Endpoint Agent
    • PDP: Agent Monitoring Network Traffic
  • PEP: VPN Appliance
  • PEP: Security Overlay


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