A Citrix ADC cluster is formed by grouping Citrix ADC appliances together. Based on the network location of the Citrix ADC appliances that you intend adding to the cluster, you must be aware of the following cluster setups:
Unless specified otherwise, cluster features and configurations are the same for L2 and L3 clusters.
L2 cluster: In this cluster deployment, all cluster nodes belong to the same network.
L3 cluster (also referred to as ‘cluster in INC mode’): In this cluster deployment, cluster nodes can belong to different networks. The cluster nodes from a specific network must be grouped into nodegroups that include only nodes from that network. From the following figure, we see that nodes n1, n2, n3 are in the same network and are grouped into Nodegroup1.
Similarly, the case for nodes n4 and n5, that are grouped in Nodegroup2. In the third network, there are two nodegroups. Nodegroup3 includes n6 and n7 and Nodegroup4 includes n8 and n9.
Supported from NetScaler 11.0 onwards.