Enterasys 9034385, Design Manual

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Model 3: End-System Authorization with Assessment
2-8 NAC Deployment Models
A RADIUS server is only required if out ‐ of ‐ band network access control using the NAC Gateway,
or inline network access control using the Layer 2 NAC Controller, is implemented with web ‐
based and/or 802.1X authentication.
NetSight Policy Manager is required for all inline NAC deployments, and recommended for out ‐
of ‐ band NAC deployments that utilize Enterasys policy ‐ capable switches. Policy Manager
provides the ability to centrally define and configure the authorization levels or policies.
NetSight Inventory Manager is an optional component, providing comprehensive network
inventory and change management capabilities.
Model 3: End-System Authorization with Assessment
This NAC deployment model implements the detection, authentication, assessment and
authorization NAC functionalities for connecting end ‐ systems. In Model 2, end ‐ systems and end
users connected to the network are authorized based on the device identity, user identity, and/or
location information. Model 3 extends the authorization decision in NAC to one additional
dimension — the security posture of the end ‐ system as determined from an assessment. The
assessment can be executed through agent ‐ based or agent ‐ less techniques and can identify
different pieces of information about the device, such an antivirus software configuration,
operating system patches installed, software applications installed and running, processes
running, services configured, and registry values set.
It is important to note that it is not necessary to configure the Enterasys NAC solution to
quarantine end ‐ systems that fail assessment. In fact, during the initial rollout of NAC on the
enterprise network, it is highly recommended that end ‐ systems are not restricted access to the
network in any way before, during, or after failed assessment. This passive NAC configuration
allows the IT administrator to baseline the configuration of devices on the network and
understand the current landscape of its assets without impacting network connectivity for
connecting end ‐ systems. In this configuration, it is not necessary to inform the end users that they
are being assessed or have failed assessment because there is little ‐ to ‐ no impact on network
connectivity during this assessment. End ‐ systems can be scanned in the background providing
the network administrator with important visibility into how devices are configured on their
network, while end users can utilize the network as desired. Then, when the network
administrator is ready, the Enterasys NAC solution can be configured with the click of a button to
immediately restrict access for end ‐ systems that have failed assessment.
Implementation
In Model 3, end ‐ systems can be detected and tracked, authenticated, assessed, and authorized in
different ways depending on whether inline or out ‐ of ‐ band network access control is
implemented in the Enterasys NAC solution.
Out-of-Band NAC
For out ‐ of ‐ band Enterasys NAC deployments utilizing the NAC Gateway, NAC functions are
implemented in the following way:
Detection ‐ As described in Model 2.
Authentication ‐ As described in Model 2.
Assessment ‐ The NAC Gateway can leverage either local assessment services and/or remote
assessment services deployed on the network. The NAC Gateway ʹ s local assessment services
include agent ‐ less assessment which can execute various server ‐ side checks (whether an FTP