In general, matcher policies can be used to find out if a parameter is included in a list (or which elements of a list correspond to a certain parameter), and influence the behavior of the proxy class based on the results. Matchers can be used for a wide range of tasks, for example, to determine if the particular IP address or URL that a client is trying to access is on a black or whitelist, or to verify that a particular e-mail address is valid. The matchers usable in a proxy class are described in the Proxedo Network Security Suite 1.0 Reference Guide.

Figure 6.61. Matcher policies

Application-level Gateway has a number of predefined matcher classes; and it is also possible to make complex decisions from the results of individual matchers using the CombineMatcher class. The available predefined classes are listed below.

Apart from the predefined ones, it is also possible to create custom matcher classes. The various matcher classes and their uses are described in the subsequent sections. The use of matchers in proxy classes is discussed in Section 6.7.4.7, Using matcher classes in proxy classes.