Clustering

IP addressing for a cluster

In addition to the standard types of Citrix ADC-owned IP addresses—Citrix ADC NSIP, Virtual IP (VIP), and Subnet IP (SNIP)—a clustered Citrix ADC appliance can have a cluster management IP (CLIP) address. It can also have striped and spotted IP addresses.

  • CLIP address. An IP address owned by the cluster coordinator node (CCO). The CLIP address can float between different nodes in a cluster setup. If the CLIP is moved to a different node of the cluster, that node becomes the CCO. The CCO is the Citrix ADC appliance that is responsible for management tasks in the cluster. A network administrator uses the CLIP address to connect to the cluster to perform configuration and management tasks, such as accessing the unified GUI, reporting, tracing packet flow, and collecting logs. You can add multiple CLIP addresses in a cluster on the same or different networks. Only configurations performed on the CCO through the cluster IP address are propagated to other nodes in the cluster.

  • Striped IP address. A logical IP address available on all nodes of the cluster, it can be either a VIP or SNIP address.

  • Spotted IP address. A logical IP (preferably SNIP address) is available only on one node. A spotted IP address has visibility on only that node. To minimize traffic-steering overhead, Citrix recommends that you use a spotted SNIP address for back-end communication with the server.

The following table provides the details of the configurations.

IP Address NSIP VIP SNIP
Spotted Yes Yes Yes
Striped No Yes Yes

For example, in a four-node cluster group, you must configure each node with a spotted SNIP address. For more information on how to configure a spotted IP configuration, see Striped, Partially Striped, and Spotted Configurations.

You can define a SNIP address to be active on only one node, or active on all nodes. If the virtual IP address and subnet IP address are available only on a specific node, it is of spotted configuration. The configuration is defined as striped if the subnet IP address and virtual server IP address are available on all nodes. Spotted SNIP addresses help in reducing the steering and backplane traffic.

Best practices for VLAN bindings and route configuration while joining a node to the cluster

VLAN IP bindings

When you bind a VLAN with spotted IP address, the Citrix ADC cluster must be configured with the spotted IP addresses in the same subnet on all the nodes. For example, in a two-node cluster with Node 0 and Node 1, you can have the following configuration:

add ns ip 192.254.101.101 255.255.255.0 -vServer DISABLED -dynamicRouting ENABLED -ownerNode 1
add ns ip 192.254.101.102 255.255.255.0 -vServer DISABLED -dynamicRouting ENABLED -ownerNode 0
add vlan 100
bind vlan 100 -IPAddress 192.254.101.101 255.255.255.0

Routing configuration

When routing configuration is required with the spotted IP address as the default gateway, then ADC cluster must be configured with the spotted IP addresses in the same subnet on all the nodes. For example, in a two-node cluster with Node 0 and Node 1, you can have the following configuration:

add ns ip 192.254.101.101 255.255.255.0 -vServer DISABLED -dynamicRouting ENABLED -ownerNode 1
add ns ip 192.254.101.102 255.255.255.0 -vServer DISABLED -dynamicRouting ENABLED -ownerNode 0

add route 192.254.102.0 255.255.255.0 192.254.101.103

Note

In an L3 cluster setup, only spotted SNIP configuration is supported.

IP addressing for a cluster