Chapter 3 Configuring Advanced Expressions: Getting Started 59
4. Click the Prefix icon (the house) and select the first expression prefix from
the drop-down list. For example, in Responder, the options are HTTP,
SYS, and CLIENT. The next set of applicable options appear in a drop-
down list.
5. Double-click the next option to select it, and then type a period (.). Again, a
set of applicable options appears in another drop-down list.
6. Continue selecting options until an entry field (signalled by parentheses)
appears. When you see an entry field, enter an appropriate value in the
parentheses. For example, if you select GT(in t) (greater-than, integer
format), you specify an integer in the parentheses. Text strings are delimited
by quotation marks. Following is an example:
HTTP.REQ.BODY(1000).BETWEEN("this","that")
7. To insert an operator between two parts of a compound expression, click
the Operators icon (the sigma), and select the operator type. Following is
an example of a configured expression with a Boolean OR (signalled by
double vertical bars, ||):
HTTP.REQ.URL.EQ("www.mycompany.com")||HTTP.REQ.BODY(1
000).BETWEEN("this","that")
8. To insert a named expression, click the down arrow next to the Add icon
(the plus sign) and select a named expression.
9. To configure an expression by using drop-down menus, and to insert built-
in expressions, click the Add icon (the plus sign). The Add Expression
dialog box works in a similar way to the main dialog box, but it provides
drop-down lists for selecting options, and it provides text fields for data
entry instead of parentheses. This dialog box also provides a Frequently
Used Expressions drop-down list that inserts commonly used expressions.
When you are done adding the expression, click OK.
10. When finished, click Create.
To test an advanced policy expression by using the configuration utility
1. In the navigation pane, click the name of the feature for which you want to
configure a policy (for example, you can select Integrated Caching,
Responder, DNS, Rewrite, or Content Switching), and then click
Policies.
2. Select a policy and click Open.
3. To test the expression, click the Advanced Expression Evaluator icon (the
check mark).
4. In the Advanced Expression Evaluator dialog box, select the Flow Type
that matches the expression.