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Central Management

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Central Management

NAC 800 uses clusters and servers. A cluster is a logical grouping of one or 
more Enforcement servers (ESs) that are managed by one Management server 
(MS). 

The quarantine method is defined per cluster; all of the Enforcement servers 
in a given cluster use the same quarantine method (Inline, DHCP, or 802.1X). 
When using multiple clusters, each cluster can have a different quarantine 
method. Clusters cooperate to test and control access to the network.

Physical Deployment

NAC 800 installs in one of the following ways: 

Inline – When deploying NAC 800 inline, NAC 800 monitors and 
enforces all device traffic. When NAC 800 is deployed as a single-
server installation, NAC 800 becomes a Layer 2 bridge that requires 
no changes to the network configuration settings. When NAC 800 is 
installed in a multiple-server installation, you might have to configure 
the switch that connects the NAC 800 enforcement servers to use 
Spanning Tree Protocol (STP) if STP is not already configured. 

NAC 800 allows devices to access the network or blocks devices from 
accessing the network based on their Internet Protocol (IP) address 
with a built-in firewall (iptables).

DHCP – When deploying NAC 800 inline with a Dynamic Host Config-
uration Protocol (DHCP) server, all DHCP requests pass through the 
NAC 800 server(s) Layer 2 bridge. For a quarantined device, NAC 800 
distributes the quarantined IP address for the device. If NAC 800 
allows the device to have access, NAC 800 allows your real DHCP 
server to distribute a non-quarantined IP address. NAC 800 assigns a 
DHCP IP address based on the quarantine area parameters you define 
during configuration. You can place restrictions on network access 
either at the gateway for the device using Access Control Lists (ACLs), 
or on the device by removing the device

'

s gateway and adding static 

routes for accessible networks.

802.1

X

 – When deploying NAC 800 in an 802.1

X

 environment, you must 

install it where it can communicate with the Remote Authentication 
Dial-In User Service (RADIUS) server (or, NAC 800 has a built-in 

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