Enterasys Networks 9034385 - Manual (Page 46)

Scenario 2: Intelligent Wireless Access Edge
3-8 Use Scenarios
Scenario 2 Implementation
In the intelligent wireless access edge use scenario, the five NAC functions are implemented in the
following manner:
1. Detection ‐ The userʹs end‐system connects to the network. The wireless switch or thick AP
sends a RADIUS authentication request (802.1X, web‐based, or MAC authentication) with the
associated credentials to the NAC Gateway.
2. Authentication ‐ If the end‐system is authenticating to the network using 802.1X or web‐based
authentication, the NAC Gateway proxies the RADIUS authentication request to a backend
authentication (RADIUS) server to validate the identity of the end user/device. For end‐systems
that are MAC authenticating to the network, the NAC Gateway may be configured to either proxy
the MAC authentication requests to the RADIUS server, or locally authorize MAC authentication
requests. If only MAC authentication is deployed on the network and the NAC Gateway is
configured to locally authorize MAC authentication requests, a backend RADIUS server is not
required with the Enterasys NAC solution.
3. Assessment ‐ After the identity of the end‐system or end user is validated via authentication,
the NAC Gateway requests an assessment of the end‐system according to predefined security
policy parameters. The assessment can be agent‐based or agent‐less, and is executed locally by the
NAC Gatewayʹs assessment functionality and/or remotely by a pool of assessment servers.
4. Authorization ‐ Once authentication and assessment are complete, the NAC Gateway allocates
the appropriate network resources to the end‐system based on authentication and/or assessment
results. For Enterasys policy‐enabled wireless switches and access points, the NAC Gateway
formats information in the RADIUS authentication messages that directs the edge switch to
dynamically assign a particular policy to the wireless end‐system on the wireless switch or AP,
depending on the type of wireless implementation. For RFC 3580‐capable wireless switches and
APs, the NAC Gateway formats information in the RADIUS authentication messages (in the form
of RFC 3580 VLAN Tunnel attributes) that directs the edge switch to dynamically assign a
particular VLAN to the wireless end‐system. If authentication fails and/or the assessment results
indicate a noncompliant end‐system, the NAC Gateway can either deny the end‐system access to
the network by sending a RADIUS access reject message, or quarantine the end‐system by
assigning a Quarantine policy or VLAN to the wireless end‐system.
5. Remediation ‐ When the quarantined end user opens a web browser to any web site, its traffic is
dynamically redirected to a Remediation web page that describes the compliance violations and
provides remediations steps for the user to execute in order to achieve compliance. After taking
the appropriate remediation steps, the end user clicks on a button on the web page to reattempt
network access, forcing the re‐assessment of the end‐system. At this point, the Enterasys NAC
solution transitions the end‐system through the entire NAC cycle of detection, authentication,
assessment, and authorization, re‐assessing the security posture of the end‐system to determine if
the remediation techniques were successfully followed. If the end‐system is now compliant with
network security policy, the NAC Gateway authorizes the end‐system with the appropriate access
policy. If the end‐system is not compliant, the end‐system is restricted access to the network and
the process starts again.