For connecting a NetApp cluster node to a Nexus switch, specific cabling types and lengths are supported to ensure signal integrity and performance.

1. Passive Twinax (Direct Attach Copper - DAC): These cables are supported for short-distance, in-rack connections. The maximum supported length is 5 meters due to signal attenuation.

2. Active Optical Cables (AOC): For distances exceeding the passive Twinax limit, AOCs are a supported option. A 7-meter length is a standard and valid choice.

3. Fiber Optic Cables: When paired with appropriate optical transceivers (e.g., QSFP+ SR4), OM4 multimode fiber cables are supported for much longer distances. A 5-meter cable is a perfectly valid implementation.

These three choices represent distinct and officially supported cabling solutions for a NetApp cluster interconnect.

C. seven meter passive Twinax cable: Passive Twinax cables are not supported beyond 5 meters for NetApp cluster interconnects due to excessive signal degradation, which can lead to instability and performance issues.

E. seven meter OM4 fiber optic cable: While technically a valid and functional option (as OM4 supports much longer distances), it represents the same technology as option B. In the context of selecting three distinct supported solutions, this option is redundant.

1. NetApp Support Knowledge Base, Article 1013420, "FAQs: Cables, SFP, SFP+, QSFP, QSFP28, QSFP-DD and other transceivers" (Version 12.0, Last updated: 18-Sep-2023):

In the "General Questions" section, it states, "Passive Direct Attached Copper (DAC) cables are available in lengths up to 5 meters. Active DAC cables are available in lengths up to 10 meters." This directly supports that 5m passive Twinax (D) is allowed and 7m passive Twinax (C) is not.

2. NetApp Hardware Universe (HWU):

When configuring NetApp controllers (e.g., AFF A-Series, FAS8300) with 40GbE or 100GbE cluster interconnect ports, the tool lists supported cables. For example, part number X6564-R6 is a 7m QSFP+ Active Optical Cable, confirming option (A). The tool also shows passive copper cables are only available up to 5m for QSFP+ and 3m for QSFP28, reinforcing the limit.

3. Cisco Validated Design, "FlexPod Datacenter with VMware vSphere 7.0... and NetApp AFF A-Series... Design Guide" (CVD-1593, Published: August 2020):

In the "Solution Design" chapter, section "NetApp AFF A-Series Storage Controllers," the guide discusses physical connectivity. It specifies the use of "Twinax cables for short distance connections and fiber cables for long distance connections," validating the use of both technologies. It further notes that for cluster interconnects, "NetApp supports Twin-AX copper cables, active optical cables (AOC), and fiber optic cables with transceivers," confirming the validity of the technologies in options A, B, and D.