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About rules, rule elements, and attributes, Nac attribute data types – Cisco 3.3 User Manual

Page 591

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14-19

User Guide for Cisco Secure ACS for Windows Server

78-16592-01

Chapter 14 Network Admission Control

NAC Policies

About Rules, Rule Elements, and Attributes

A rule is a set of one or more rule elements. A rule element is a logical statement
consisting of the following three items:

A posture validation attribute

An operator

A value

Cisco Secure ACS uses the operator to compare the contents of an attribute to the
value. Each rule element of a rule must be true for the whole rule to be true. In
other words, all rule elements of a rule are “anded” together.

This section contains the following topics:

NAC Attribute Data Types, page 14-19

Rule Operators, page 14-20

NAC Attribute Data Types

Posture validation attributes can be one of the following data types:

boolean—The attribute can contain a value of either 1 or 0 (zero). In the
HTML interface, when you define a rule element with a boolean attribute,
valid input are the words

false

and

true

. Valid operators are = (equal to) and

!= (not equal to). When a rule element using a boolean attribute is evaluated,

false

corresponds to a value of 0 (zero) and

true

corresponds to 1.

For example, if a rule element for a boolean attribute requires that the
attribute is not equal to

false

and the attribute in a specific posture validation

request was 1, Cisco Secure ACS would evaluate the rule element to be true;
however, to avoid confusion, you can express the rule element more clearly
by requiring that the attribute is equal to

true

.

string—The attribute can contain a string. Valid operators are = (equal to), !=
(not equal to), contains, starts-with, and regular-expression.

integer—The attribute can contain an integer, including a signed integer.
Valid operators are = (equal to), != (not equal to), > (greater than), < (less
than), <= (less than or equal to), >= (greater than or equal to). Valid input in
rule elements is an integer between -65535 and 65535.