Striped, partially striped, and spotted configurations
By virtue of command propagation, all nodes in a cluster have the same configurations. However, you might want some configurations to be available only on certain cluster nodes. While you cannot restrict the nodes on which the configurations are available, you can specify the nodes on which the configurations are active.
For example, you can:
- define a SNIP address to be active on only one node, or
- define a SNIP address to be active on all nodes, or
- define a VIP address to be active on only one node, or
- define a VIP address to be active on all nodes, or
- define a VIP address to be active only on two nodes of a 3-node cluster
Depending on the number of nodes the configurations are active on, cluster configurations are referred to as striped, partially striped, or spotted configurations.
Figure 1. Three-node cluster with striped, partially striped, and spotted configurations
The following table provides more details on the types of configurations:
|Configuration Type||Active on||Applicable to||Configurations|
|Striped configuration||All the cluster nodes||All entries||No specific configuration required to make an entity striped. By default, all entities defined on a cluster IP address are striped on all the cluster nodes.|
|Partially striped configuration||A subset of cluster nodes||Refer Cluster Nodegroups.||Bind the entities that you want to be partially striped, to a node group. The configuration is active only on the cluster nodes that belong to the node group.|
|Spotted configuration||Single cluster node||SNIP address; SNMP Engine ID; Hostname of cluster nodes; Entities that can be bound to a node group||A spotted configuration can be defined using one of two approaches. SNIP address When creating the SNIP address, specify the node on which you want the SNIP address to be active, as the owner node. Example, add ns ip 10.102.29.106 255.255.255.0 -type SNIP -ownerNode 2 (assuming node NS2 ID is 2). Note: You cannot change the ownership of a spotted SNIP address at run time. To change the ownership, you must first delete the SNIP address and add it again by specifying the new owner. Entities that can be bound to a node group. By binding the entity to a single-member node group.|
When you disable USIP, Citrix recommends you to use spotted SNIP addresses. You can use striped SNIP addresses only if there is a shortage of IP addresses. The use of striped IP addresses can result in ARP flux issues if no spotted IP addresses are present in the same subnet for ARP resolution.
When you enable USIP, Citrix recommends you to use striped SNIP addresses as a gateway for server initiated traffic.
ARP owner support for striped IP
In a cluster setup, you can now configure a specific node to respond to the ARP request for a striped IP. The configured node will respond to the ARP traffic.
A new parameter “arpOwner” is introduced in the “add, set, and unset ip” commands.
To enable ARP owner on a node by using the CLI.
At the command prompt, type:
add ns ip <ip_address> -arpOwner <node_id>
The ARP owner parameter is supported only in L2 cluster.