Verify that the appliance is licensed for content switching.

Verify that the feature is enabled.

From the configuration file, verify that valid content switching policies are correctly bound to the load balancing virtual servers.

Verify the URL and policy bindings. The client receives the 503 response when none of the policies you have configured is evaluated and no default load balancing virtual server is defined and bound to the content switching virtual server.

From the configuration, verify the policies and the URL is accessed by the client.

Verify that for every type of request the respective policy is evaluated. If the policy is not evaluated, check the policy expression and update it if necessary.

Verify the URL and HTTP request and response headers. To do so, record an HTTPHeader trace and, if necessary, record the packet traces on the appliance and the client.

Study the network topology diagram, if available, of the setup to understand the various devices installed between the client and the servers.

Verify the configuration and policy bindings. Make sure that the URL in the policy expression matches to the one in the client request.

Verify that appropriate priorities are assigned to the policies. An incorrect precedence or priority assigned to a policy can cause a problem.

Run the following commands to verify the bindings and the values of the policy select counters in the output of the commands:

show cs vserver \<CS VServer\>

show cs policy \<CS Policy\>

stat cs vserver \<CS VServer\>

Using iehttpheaders or a similar utility, determine whether the HTTP headers for the requests or responses provide any pointers to the issue.

Check the release notes and Knowledge Center articles.

If the issue is still not resolved, contact Citrix® technical support with appropriate data for further investigation.