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In-Band ACP Setup and Support

Last Updated:

Applies to

  • DS2246
  • DS4486
  • DS4246


The Alternate Control Path (ACP) interface currently uses Ethernet-based network connectivity to perform various recovery tasks, such as expander resets and shelf power cycles. This feature was referred to as Out-of-Band (OOB) ACP. With ONTAP 9.0 and later, ACP uses available SAS data links to perform the same tasks. This feature is referred to as In-Band ACP. The ACP mode that is configured applies to the entire ONTAP cluster.

This article outlines how to migrate from OOB to In-Band ACP support - the default in ONTAP 9.0 and later.

Several areas need to be considered before migration:

  1. All IOM6 I/O modules must be upgraded to 2.09 or later.

  2. ACP firmware (protocol version or later.

  3. All IOM6E I/O modules must be upgraded to 1.60 shelf firmware or later.

  4. FAS22xx and FAS25xx systems must be running 2.4 SP firmware or later.

  5. There must be dual path to each IOM to support In-Band ACP

  6. The storage controller must not have the ATTO bridge between the controller and the shelf to support In-Band ACP.

  7. Starting with AFF A700, AFF A300, AFF A200 and FAS9000, FAS8200, and FAS2600 series storage systems, OOB ACP is not supported.

  8. SAS3 (12Gb/s) shelves with IOM12 I/O modules do not support OOB ACP.

  9. SAS2 (3/6Gb/s) storage with IOM3 I/O modules do not support In-Band ACP.

Regarding the restrictions described by #8 and #9, the configuration options for a cluster are as follows:

  1. Upgrade IOM3-based storage to IOM6 or IOM12-based storage to provide In-Band ACP support for all storage (recommended by NetApp).

  2. Continue using OOB ACP, but not In-Band ACP support for SAS3 storage.

  3. Migrate to In-Band ACP, but not ACP support for IOM3-based storage.

Important: This does not apply to MetroCluster configurations.
Inband ACP is supported in MetroCluster if both of the below apply:

  1. ATTO 7500N or 7600N FibreBridges are being used
  2. IOM12 based storage modules are used