Enterasys Networks 9034385 - Manual (Page 54)

Survey the Network
4-2 Design Planning
access to a web browser to safely remediate their quarantined end‐system without impacting
IT operations.
Once a deployment model is selected, the current network infrastructure must be examined to
identify the technical dependencies and requirements imposed by the NAC solution.
Survey the Network
The steps in this section will help you identify and evaluate the current network infrastructure so
that you can make design decisions regarding NAC component requirements.
1. Identify the Intelligent Edge of the Network
The first step in surveying your network is to determine whether or not your network has an
“intelligent edge.” This information will help you decide whether the NAC Gateway or NAC
Controller appliance best suits your network infrastructure.
The term “intelligent” refers to a network topology where the access edge is composed of
Enterasys policy‐enabled switches capable of supporting authentication and policy enforcement,
or third‐party switches capable of supporting authentication and dynamic VLAN assignment as
defined in RFC 3580.
Non‐intelligent infrastructure devices, such as repeaters and hubs, are not capable of supporting
authentication and/or authorization of end‐systems, and simply provide connectivity to the
infrastructure.
An intelligent edge is required when the NAC Gateway is utilized for implementing out‐of‐band
NAC. The NAC Gateway appliance leverages the intelligent edge of the network to implement the
authentication and authorization of connecting end‐systems. The NAC Gateway effects the
assignment of policies or VLANs on Enterasys switches or RFC 3580‐capable switches located at
edge of the network, to authorize a level of network access to connecting end‐systems. These
assignments are based on various parameters, such as the location of the end‐system and security
posture assessment results. The intelligent edge of the network also implements an authentication
method (802.1X, web‐based, or MAC authentication) for validating the device and/or user identity
of connecting end‐systems.
However, in networks with non‐intelligent devices at the access edge, it is not necessary to replace
these non‐intelligent devices to be able to implement out‐of‐band NAC with the NAC Gateway.
Instead, the Enterasys Matrix N‐series switch can be positioned upstream from non‐intelligent
devices (such as in the distribution layer) to implement the authentication and authorization
functions for downstream connected devices. Matrix N‐Series devices support Multi‐User
Authentication (MUA) which enables the switch to individually authenticate and uniquely
authorize multiple end‐systems connected to the same physical port. MUA on the Matrix N‐series
Platinum supports the concurrent authentication and authorization of over 1000 end‐systems on a
single port with the allocation of disparate network resources to each end‐system. In this case, the
Matrix N‐series switch is the intelligent edge of the network although it is not physically located in
the access layer. By utilizing the Matrix N‐series in this type of configuration, most of the benefits
of out‐of‐band NAC can be obtained without upgrading the edge of the network.