Chapter 2 Configuring Advanced Policies 19
balancing virtual servers, the NetScaler process the response-time policies
for content switching virtual servers.
8. Response-time default. If policy evaluation cannot be completed after all
response-time, virtual-server-specific policies have been evaluated, the
NetScaler processes response-time default policies.
Advanced Policy Evaluation Across Features
In addition to attending to evaluation of policies within a feature, if you have
bound policies to a content switching virtual server, note that these policies are
evaluated before other policies. Binding a policy to a content switching vserver
produces a different result in NetScaler versions 9.0.x and later than in 8.x
versions. In NetScaler 9.0 and later versions, evaluation occurs as follows:
• Content switching policies are evaluated before other policies. If a content
switching policy evaluates to TRUE, the target load balancing vserver is
selected.
• If all content switching policies evaluate to FALSE, the default load
balancing vserver under the content switching VIP is selected.
After a target load balancing vserver is selected by the content switching process,
policies are evaluated in the following order:
1. Policies that are bound to the global override bind point.
2. Policies that are bound to the default load balancing vserver.
3. Policies that are bound to the target content switching vserver.
4. Policies that are bound to the global default bind point.
To be sure that the policies are evaluated in the intended order, follow these
guidelines:
• Make sure that the default load balancing vserver is not directly reachable
from the outside; for example, the vserver IP address can be 0.0.0.0.
• To prevent exposing internal data on the load balancing default vserver,
configure a policy to respond with a “503 Service Unavailable” status and
bind it to the default load balancing vserver.
Entries in a Policy Bank
Each entry in a policy bank has, at minimum, a policy and a priority level. You
can also configure entries that change the priority-based evaluation order, and you
can configure entries that invoke external policy banks.