Cisco Systems Setting Global NAC Parameters

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Cisco ASA 5500 Series Configuration Guide using ASDM
Chapter68 Configuring IKE, Load Balancing, and NAC
Setting Global NAC Parameters
Setting Global NAC Parameters
The ASA uses Extensible Authentication Protocol (EAP) over UDP (EAPoUDP) messaging to validate
the posture of remote hosts. Posture validation involves checking a remote host for compliancy with
safety requirements before the assignment of a network access policy. An Access Control Server must
be configured for Network Admission Control before you configure NAC on the ASA.
Fields
The NAC pane lets you set attributes that apply to all NAC communications. The following global
attributes at the top of the pane apply to EAPoUDP messaging between the ASA and remote hosts:
•Port—Port number for EAP over UDP communication with the Cisco Trust Agent (CTA) on the
host. This number must match the port number configured on the CTA. Enter a value in the range
1024 to 65535. The default setting is 21862.
•Retry if no response—Number of times the ASA resends an EAP over UDP message. This attribute
limits the number of consecutive retries sent in response to Rechallenge Interval expirations. The
setting is in seconds. Enter a value in the range 1 to 3. The default setting is 3.
•Rechallenge Interval—The ASA starts this timer when it sends an EAPoUDP message to the host.
A response from the host clears the timer. If the timer expires before the ASA receives a response,
it resends the message. The setting is in seconds. Enter a value in the range 1 to 60. The default
setting is 3.
•Wait before new PV Session—The ASA starts this timer when it places the NAC session for a remote
host into a hold state. It places a session in a hold state if it does not receive a response after sending
EAPoUDP messages equal to the value of the “Retry if no response” setting. The ASA also starts
this timer after it receives an Access Reject message from the ACS server. When the timer expires,
the ASA tries to initiate a new EAP over UDP association with the remote host. The setting is in
seconds. Enter a value in the range 60 to 86400. The default setting is 180.
The Clientless Authentication area of the NAC pane lets you configure settings for hosts that are not
responsive to the EAPoUDP requests. Hosts for which there is no CTA running do not respond to these
requests.
•Enable clientless authentication—Click to enable clientless authentication. The ASA sends the
configured clientless username and password to the Access Control Server in the form of a user
authentication request. The ACS in turn requests the access policy for clientless hosts. If you leave
this attribute blank, the ASA applies the default ACL for clientless hosts.
•Clientless Username—Username configured for clientless hosts on the ACS. The default setting is
clientless. Enter 1 to 64 ASCII characters, excluding leading and trailing spaces, pound signs (#),
question marks (?), single and double quotation marks (“ ” and "), asterisks (*), and angle brackets
(< and >).
•Password—Password configured for clientless hosts on the ACS. The default setting is clientless.
Enter 4 – 32 ASCII characters.
•Confirm Password—Password configured for clientless hosts on the ACS repeated for validation.
Firewall Mode Security Context
Routed Transparent Single
Multiple
Context System
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