Note: Application firewall support for Striped and partially striped configurations was introduced in NetScaler release 11.0.
A cluster is a group of NetScaler appliances that are configured and managed as a single system. Each appliance in the cluster is called a node. Depending on the number of nodes the configurations are active on, cluster configurations are referred to as striped, partially striped, or spotted configurations. The application firewall is fully supported in all configurations.
Security checks and signature protections can be deployed without the need for any additional cluster-specific application firewall configuration. You just do the usual application firewall configuration on the configuration coordinator (CCO) node for propagation to all the nodes.
Cluster details are available at http://support.citrix.com/proddocs/topic/ns-system-11-map/ns-cluster-home-con.html.
Note: The session information is replicated across multiple nodes, but not across all the nodes in the striped configuration. Therefore, failover support accommodates a limited number of simultaneous failures. If multiple nodes fail simultaneously, the application firewall might lose the session information if a failure occurs before the session is replicated on another node.