Citrix Systems Network Router 9.2 Manual De Usuario
Chapter 3 Configuring Advanced Expressions: Getting Started
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Which expression prefixes you can specify depends on the NetScaler feature. The
following table describes the expression prefixes that are of interest on a per-
feature basis.
following table describes the expression prefixes that are of interest on a per-
feature basis.
Note:
For details on the permitted expression prefixes in a feature, see the
documentation for that feature.
Single-Element Expressions
The simplest type of advanced expression contains a single element. This element
can be one of the following:
can be one of the following:
•
true
. An advanced expression can consist simply of the value true. This
type of expression always returns a value of TRUE. It is useful for chaining
policy actions and triggering Goto expressions.
policy actions and triggering Goto expressions.
•
false
. An advanced expression can consist simply of the value false.
This type of expression always returns a value of FALSE.
•
A prefix for a compound expression. For example, the prefix
HTTP.REQ.HOSTNAME
is a complete expression that returns a host name, and
HTTP.REQ.URL
is a complete expression that returns a URL. The prefix
could also be used in conjuction with operations and additional prefixes to
form a compound expression.
form a compound expression.
Operations
In most expressions, you specify an operation on the data that the prefix
identifies. For example, suppose that you specify the following prefix:
identifies. For example, suppose that you specify the following prefix:
http.req.url
Permitted Types of Expression Prefixes in Various NetScaler Feature
Feature
Types of Expression Prefix Used in the Feature
DNS
SYS, CLIENT, SERVER
Responder in Protection
Features
Features
HTTP, SYS, CLIENT
Content Switching
HTTP, SYS, CLIENT
Rewrite
HTTP, SYS, CLIENT, SERVER, URL, TEXT,
TARGET, VPN
TARGET, VPN
Integrated Caching
HTTP, SYS, CLIENT, SERVER
Access Gateway,
Clientless Access
Clientless Access
HTTP, SYS, CLIENT, SERVER, URL, TEXT,
TARGET, VPN
TARGET, VPN