The expression consists of an expression type and the parameters of the expression. Expression types include:
NetScaler Gateway comes with pre-configured expressions, called named expressions. When you configure a policy, you can use a named expression for the policy. For example, you want the preauthentication policy to check for Symantec AntiVirus 10 with updated virus definitions. Create a preauthentication policy and add the expression as described in the following procedure.
When you create a preauthentication or session policy, you can create the expression when you create the policy. You can then apply the policy, with the expression, to virtual servers or globally.
The following procedure describes how to add a preconfigured antivirus expression to a policy by using the configuration utility.