ACP can increase your storage availability when you use SAS disk shelves. If your storage system model has a dedicated port for ACP, then ACP is enabled by default and you do not need to explicitly enable ACP.
For more information, see the Installation and Service Guide for your disk shelf.
The ACP subnet is a private Ethernet network that enables the ACP processor in the SAS module to communicate both with Data ONTAP and the SAS IOMs in the disk shelves.
The ACP subnet is separate from the I/O data path that connects the disk shelves to the HBA on the storage controller. When you configure ACP on one of the system's network interfaces, you must supply a private domain name that conforms to the standard for private internet addresses (RFC1918). You can use the system default domain or another network name (that is, an IP address ending in 0) that conforms to the standard.
For example, if you select e0P as the interface for ACP traffic, 192.168.0.0 as the ACP domain, and 255.255.252.0 as the network mask for the ACP subnet, the storage show acp command output looks similar to the following:
my-sys-1> storage show acp
Alternate Control Path: Enabled
Ethernet Interface: e0p
ACP Status: Active
ACP IP address: 192.168.2.61
ACP domain: 192.168.0.0
ACP netmask: 255.255.252.0
ACP Connectivity Status: Full Connectivity
ACP Partner Connectivity Status: NA
Shelf Module Reset Cnt IP address FW Version Module Type Status
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7a.001.A 002 192.168.0.145 01.05 IOM6 active
7a.001.B 003 192.168.0.146 01.05 IOM6 active
7c.002.A 000 192.168.0.206 01.05 IOM6 active
7c.002.B 001 192.168.0.204 01.05 IOM6 active