IP Addresses

An IP address is a 32-bit identifier for devices on a TCP/IP network. IP addresses allow devices on a network, such as servers, switches, and arrays, to communicate with each other. Arrays use IP addresses for the following purposes:

Table 1. Types of IP addresses
IP Address Purpose
Management

Typically defined on eth1 or on eth1 and eth2 interface, the management IP address provides access to the array OS management interface (GUI, CLI, or API) for the array group. It is also used for volume replication. It resides on the group management subnet and floats across all management only (Mgmt only) and management + data (Mgmt + Data) interfaces.

Secondary This is a secondary management IP address that is associated with the backup group leader array. In the event of a group leader migration or manual takeover, you can use this IP address to enable the backup group leader to take over the group leader functions. This IP address resides on the group management subnet and floats across all management only (Mgmt only) and management + data (Mgmt + Data) interfaces. While setting up a secondary management IP address is a best practice, it is optional.
Discovery

For iSCSI arrays, each subnet has its own discovery IP address. It enables the iSCSI initiator to discover iSCSI targets for the volumes on the array. You can use this IP address for data as well as management in a single shared network.

NOTE: Discovery IP addresses are not required for Fibre Channel arrays.
Data

One or more IP addresses can be configured to carry data traffic. One data IP address can be configured for each interface pair (corresponding interfaces on the two controllers). Both controllers use the same IP address but never at the same time because only one controller is active at a time. Other data IP addresses can be configured on different subnets.

NOTE: In a dedicated network topology, the data IP addresses cannot be the same as the management/iSCSI discovery IP addresses.
Support

Each controller on an array must have a dedicated support IP address, which can be used for troubleshooting and technical support purposes in the event that a controller is not reachable through the management IP address. The support IP addresses must be placed on the group management subnet.