Enterasys Networks 9034385 - Manual (Page 15)

NAC Solution Components
Enterasys NAC Design Guide 1-5
Enterasys offers two types of NAC appliances: the NAC Gateway appliance implements out‐of‐
band network access control, and the NAC Controller appliance implements inline network access
control. The following section describes how each NAC appliance implements network access
control for connecting end‐systems.
NAC Gateway Appliance
The NAC Gateway is utilized to implement out‐of‐band network access control for connecting
end‐systems. With the NAC Gateway, connecting end‐systems are detected on the network
through their RADIUS authentication interchange. Based on the assessment and authentication
results for a connecting device, RADIUS attributes are added or modified during the
authentication process to authorize the end‐system on the authenticating edge switch. Therefore,
the NAC Gateway can be positioned anywhere in the network topology with the only
requirement being that IP connectivity between the authenticating edge switches and the NAC
Gateways is operational.
The NAC Gateway requires the implementation of intelligent wired or wireless edge
infrastructure devices as the authorization point for connecting end‐systems. Intelligent edge
devices are capable of supporting authentication and authorization based on the authentication
message interchange. Depending on the appliance model, the NAC Gateway provides either
integrated assessment server functionality and/or the ability to connect to external assessment
services, to determine the security posture of end‐systems connecting to the network.
Three NAC Gateway models are available to meet the needs of different‐sized implementations
and assessment server requirements.
• SNS‐TAG‐ITA supports up to 3000 concurrent end‐systems and provides integrated
assessment servers. (A separate license is required for integrated assessment.) This integrated
NAC Gateway supports both agent‐less (network‐based) and agent‐based assessment. In
addition to having the capability to run as an integrated appliance, it also has the capability to
run as an assessment server (scanner) only. The SNS‐TAG‐ITA also supports the ability to
connect to multiple external assessment servers including Nessus and Lockdown Enforcer.
• SNS‐TAG‐HPA supports up to 3000 concurrent end‐systems and supports the ability to
connect to multiple external assessment servers including Nessus and Lockdown Enforcer.
• SNS‐TAG‐LPA supports up to 2000 concurrent end‐systems and supports the ability to
connect to multiple external assessment servers including Nessus and Lockdown Enforcer.
NAC Controller Appliance
The NAC Controller is utilized to implement inline network access control for connecting end‐
systems. With the NAC Controller, connecting end‐systems are detected through the receipt of a
packet from a new end‐system. Based on the assessment and authentication results for a
connecting device, the authorization of the end‐system is implemented locally on the NAC
Controller appliance by assigning a set of traffic forwarding rules, referred to as “policy,” to all
traffic sourced by the end‐system. The NAC Controller appliance is positioned strategically in the
network topology within the end user LAN segment or across routed boundaries, inline with data
traffic sourced from end‐systems. Since this appliance exists in the data path of networked
devices, it has been designed to achieve multi‐gigabit throughput with hardware‐based traffic
forwarding, by leveraging customized Enterasys‐built Application Specific Integrated Circuits
(ASICs).
The NAC Controller is applicable to scenarios where non‐intelligent wired or wireless edge
infrastructure devices are deployed in the network. Non‐intelligent edge devices are not capable