2 Citrix NetScaler Policy Configuration and Reference Guide
Benefits of Using Advanced Policies
Advanced policies use a powerful expression language that is built on a class-
object model, and they offer several options that enhance your ability to configure
the behavior of various NetScaler features. With advanced policies, you can do
the following:
• Perform fine-grained analyses of network traffic from layers 2 through 7.
• Evaluate any part of the header or body of an HTTP or HTTPS request or
response.
• Bind policies to the multiple bind points that the advanced policy
infrastructure supports at the default, override, and virtual server levels.
• Use goto expressions to transfer control to other policies and bind points, as
determined by the result of expression evaluation.
• Use special tools such as pattern sets, policy labels, rate limit identifiers,
and HTTP callouts, which enable you to configure policies effectively for
complex use cases.
Additionally, the configuration utility extends robust graphical user interface
support for advanced policies and expressions and enables users who have
limited knowledge of networking protocols to configure policies quickly and
easily. The configuration utility also includes a policy evaluation feature for
advanced policies. You can use this feature to evaluate an advanced policy and
test its behavior before you commit it, thus reducing the risk of configuration
errors.
Basic Components of an Advanced or a Classic Policy
Following are a few characteristics of both classic and advanced policies:
•Name. Each policy has a unique name.
•Rule. The rule is a logical expression that enables the NetScaler feature to
evaluate a piece of traffic or another object.
For example, a rule can enable the NetScaler to determine whether an
HTTP request originated from a particular IP address, or whether a Cache-
Control header in an HTTP request has the value “No-Cache”.
Advanced policies can use all of the expressions that are available in a
classic policy, with the exception of classic expressions for the SSL VPN
client. In addition, advanced policies enable you to configure more
complex expressions.