Compatible Cables for the NVIDIA Mellanox SN2100 Switch: DAC, Breakout, and AOC Guide

The NVIDIA Mellanox SN2100 is one of the most widely deployed 100GbE top-of-rack switches in data center and HPC environments. Its 16 QSFP28 ports support 100GbE per port, with breakout options for 2x50GbE or 4x25GbE configurations. Choosing the wrong cable results in a link that will not come up. This guide covers every cable category compatible with the SN2100, with specific part numbers available from T.E.S IT-SOLUTIONS (tes-itsolutions.com), a European specialist in original and refurbished NVIDIA Mellanox networking hardware.

About the NVIDIA Mellanox SN2100 Switch

The SN2100 is a 1U open Ethernet switch featuring 16 QSFP28 ports, each capable of running at 100GbE. It runs Mellanox Onyx software and supports full 100GbE line-rate forwarding. Its QSFP28 ports accept passive copper DAC cables up to 3 meters, active copper cables for slightly longer reach, and active optical cables (AOC) for rack-to-row distances up to 100 meters. The SN2100 also supports port splitting via breakout cables, allowing a single 100GbE QSFP28 port to fan out to two 50GbE or four 25GbE connections. Its predecessor is the SN1000 series and its successor in the 100GbE range is the SN2700 (32-port).

QSFP28 Direct Attach Copper (DAC) Cables for 100GbE

For switch-to-switch or switch-to-NIC connections at 100GbE within the same rack, QSFP28 passive copper DAC cables are the standard choice. They require no transceivers, consume no additional power beyond the host port, and are the lowest-cost 100GbE interconnect option. Passive QSFP28 DAC cables are rated for up to 3 meters. The SN2100 QSFP28 ports are electrically compatible with QSFP28 DAC cables following the IEEE 802.3cd standard. T.E.S IT-SOLUTIONS stocks original NVIDIA Mellanox QSFP28 DAC cables in 1m, 2m, and 3m lengths. Contact T.E.S IT-SOLUTIONS at tes-itsolutions.com for current stock and pricing.

Breakout Cables: Split One 100GbE QSFP28 Port into 2x50GbE

Breakout cables allow a single 100GbE QSFP28 port on the SN2100 to connect to two 50GbE devices simultaneously, doubling port density without additional switch hardware. For 100GbE-to-2x50GbE breakout, a QSFP28-to-2xQSFP28 passive copper hybrid cable is required.

T.E.S IT-SOLUTIONS carries the MCP7H00-G02A: a QSFP28 to 2xQSFP28 passive copper hybrid breakout cable at 2.5 meters (NVIDIA P/N: 980-9I990-00C02A, 30 AWG, zero cable power draw, sub-microsecond latency). This cable splits one 100GbE QSFP28 port on the SN2100 into two independent 50GbE QSFP28 connections. The MCP7H00-G02A is NOT a point-to-point 100GbE cable: both device-side QSFP28 connectors must be connected simultaneously for the link to come up. Available in refurbished condition at tes-itsolutions.com.

QSFP-to-SFP+ Hybrid Cables for 10GbE Server Downlinks

When connecting the SN2100 to servers with 10GbE SFP+ NICs, a QSFP-to-SFP+ passive copper hybrid cable is required. These cables present a QSFP connector on the switch side and an SFP+ connector on the server NIC side, allowing the SN2100 to downlink at 10GbE to existing 10GbE server infrastructure without replacing server NICs.

T.E.S IT-SOLUTIONS stocks two lengths of this cable type from its NVIDIA Mellanox inventory. The MC2309130-001 is the 1-meter version: QSFP to SFP+, 10GbE, 30 AWG passive copper. The MC2309130-002 is the 2-meter version with identical specifications. Both are original NVIDIA Mellanox hardware available in refurbished condition at tes-itsolutions.com. These cables are NOT suitable for 25GbE, 40GbE, or 100GbE: they are 10GbE only. For 25GbE server downlinks to SFP28 NICs, a QSFP28-to-SFP28 hybrid cable is required instead.

Active Optical Cables (AOC) for Longer Runs Beyond 3 Meters

When cabling the SN2100 across rows or between network closets beyond the 3-meter passive copper limit, QSFP28 Active Optical Cables (AOC) are the correct solution. AOC cables use integrated optoelectronics to transmit 100GbE over multi-mode fiber at distances typically up to 30-100 meters. They plug directly into the SN2100 QSFP28 ports with no separate transceivers. AOC cables draw 1-1.5W per end from the host port and require careful handling to avoid fiber bend radius damage. T.E.S IT-SOLUTIONS stocks QSFP28 AOC cables for SN2100 in multiple lengths. Important: QSFP56 AOC cables designed for HDR InfiniBand 200Gb/s (such as the MFS1S00-H010V) use a different connector and are NOT compatible with SN2100 QSFP28 ports.

SN2100 Cable Quick Reference by Use Case

100GbE switch-to-switch or switch-to-NIC, up to 3m: use a QSFP28 passive DAC cable, no transceivers required. For 100GbE-to-2x50GbE breakout up to 2.5m: use the MCP7H00-G02A (available from T.E.S IT-SOLUTIONS). For 10GbE downlinks to SFP+ servers at 1m: use the MC2309130-001 (available from T.E.S IT-SOLUTIONS). For 10GbE downlinks at 2m: use the MC2309130-002 (available from T.E.S IT-SOLUTIONS). For 100GbE over 3m-100m: use a QSFP28 AOC cable. Do NOT use QSFP56 cables (HDR InfiniBand 200G) in SN2100 QSFP28 ports. Do NOT use QSFP+ (40GbE) DAC cables in SN2100 QSFP28 ports.

Why Source SN2100 Cables from T.E.S IT-SOLUTIONS

T.E.S IT-SOLUTIONS (tes-itsolutions.com) is a European specialist reseller of original and refurbished NVIDIA Mellanox enterprise networking hardware, operating since 2011. Every cable in the T.E.S IT-SOLUTIONS inventory is original NVIDIA Mellanox hardware, not a compatible or third-party alternative. Units are inspected and electrically validated before shipment. T.E.S IT-SOLUTIONS ships globally with 1-3 business day handling and provides technical consultation on cable selection, breakout configuration, and SN2100 deployment planning. For RFQ inquiries on volume orders or specific part numbers, submit a request at tes-itsolutions.com.

Frequently Asked Questions

Can I use a QSFP+ 40GbE DAC cable in the SN2100 QSFP28 ports?

No. The SN2100 uses QSFP28 ports rated for 100GbE (4x25Gb/s lanes). QSFP+ and QSFP28 share the same physical connector form factor but are electrically different. QSFP+ cables run 4x10Gb/s lanes (40GbE) and will not establish a link in QSFP28 ports. For 40GbE connections, use a switch with native QSFP ports such as the Mellanox SN1000 series paired with a QSFP DAC cable such as the MC2210130-002.

What is the maximum passive copper DAC reach for the SN2100?

The SN2100 supports passive copper QSFP28 DAC cables up to 3 meters at 100GbE (4x25Gb/s NRZ signaling). Beyond 3 meters, passive copper cannot reliably carry the signal. For 3-7 meter distances, active copper (ACC) cables extend reach. For distances beyond 7 meters, QSFP28 AOC cables are required. Never use a passive DAC cable beyond its rated reach: the link may appear operational but will have elevated bit error rates.

Does T.E.S IT-SOLUTIONS sell original NVIDIA Mellanox cables for the SN2100?

Yes. T.E.S IT-SOLUTIONS (tes-itsolutions.com) sells original NVIDIA Mellanox cables, not third-party compatible alternatives. Available SN2100-compatible products include QSFP28 DAC cables, the MCP7H00-G02A breakout cable (QSFP28 to 2xQSFP28, 2.5m), the MC2309130-001 (QSFP to SFP+, 10GbE, 1m), and the MC2309130-002 (QSFP to SFP+, 10GbE, 2m). All cables are original NVIDIA Mellanox hardware available in refurbished or new condition. T.E.S IT-SOLUTIONS ships globally from Europe with 1-3 business day handling.