Enterasys Networks 9034385 - Manual (Page 31)

Model 3: End-System Authorization with Assessment
Enterasys NAC Design Guide 2-9
server is running or if the HTTP server is out‐of‐date) and client‐side checks (running
applications, software configurations, installed operating system patches) provided end‐system
administrative credentials are available for remote login to connecting devices. Additionally, the
NAC Gatewayʹs local assessment services also include agent‐based assessment using a Java Web
Start‐based client application that allows execution of server‐side and client‐side checks without
requiring administrative credentials or special host firewall configurations.
The NAC Gatewayʹs remote assessment services include agent‐less and agent‐based assessment
on other NAC Gateways deployed on the network and/or third‐party vulnerability scanners such
as Nessus and Lockdown Enforcer. As end‐systems connect to the network, assessments can be
load‐balanced among all of the configured assessment services or a defined pool. This provides
maximum scalability and flexibility, and minimizes the amount of time necessary to complete an
end‐system assessment.
Authorization ‐ The NAC Gateway allocates the appropriate network resources to the end‐system
based on authentication, location, and/or assessment results. For Enterasys policy‐enabled edge
switches, the NAC Gateway formats information in the RADIUS authentication messages that
directs the edge switch to dynamically assign a particular policy to the connecting end‐system. For
RFC 3580‐capable edge switches, 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 connecting 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 to
the edge switch or quarantine the end‐system with a highly restrictive set of network resources (or
possibly permit network access) by specifying a particular policy or VLAN to assign to the
authenticated end‐system on the edge switch.
Inline NAC
For inline Enterasys NAC deployments utilizing the Layer 2 or Layer 3 NAC Controller, the NAC
functions are implemented in the following way:
Detection ‐ As described in Model 2.
Authentication ‐ As described in Model 2.
Assessment ‐ The NAC Controller can leverage either local assessment services and/or remote
assessment services deployed on the network, as previously described for the NAC Gateway. The
NAC Controllerʹs local assessment services include agent‐less assessment which can execute
various server‐side checks and client‐side checks. Local assessment services also include agent‐
based assessment using a Java Web Start‐based client application that allows execution of server‐
side and client‐side checks. The NAC Controllerʹs remote assessment services include agent‐less
and agent‐based assessment with NAC Gateways and/or third‐party vulnerability scanners such
as Nessus and Lockdown Enforcer. As end‐systems connect to the network, assessment can be
load‐balanced among all of the configured assessment services to provide maximum scalability
and flexibility while minimizing assessment times.
Authorization ‐ The NAC Controller allocates the appropriate network resources to the end‐
system based on authentication and/or assessment results. This is implemented by assigning a
policy to traffic sourced from the end‐system locally on the controller. If authentication fails and/
or the assessment results indicate a noncompliant end‐system, the NAC Controller can either
deny the end‐system access to the network, quarantine the end‐system with a highly restrictive set
of network resources, or permit network access by specifying a particular policy.