NVIDIA Mellanox MSN2740-CB2F1O 100GbE 1U Spectrum-based Open Ethernet Switch with ONIE: This is a 1U Open Ethernet leaf/top-of-rack switch built on the Mellanox Spectrum ASIC, providing 32 QSFP28 ports for 100GbE deployments in a short-depth chassis. The "1O" suffix denotes factory-loaded ONIE (Open Network Install Environment) — the unit ships without a production NOS preinstalled and is intended for sites that will install Cumulus Linux, SONiC, NVIDIA Onyx (with separate license) or another ONIE-compatible OS. This is a top-of-rack switch, not an aggregation/spine chassis. This is a refurbished unit.
Engineering Context
The Spectrum ASIC supports non-blocking line-rate Layer 2 and Layer 3 forwarding across all 32 QSFP28 ports. Each QSFP28 port can be operated at 100GbE, 50GbE, 40GbE, 25GbE or 10GbE depending on the connected optic or breakout cable. Port-to-port latency is in the sub-300 ns range typical of Spectrum platforms. The chassis includes 2 hot-swappable AC power supplies for N+1 redundancy and an x86 management CPU. Forward (P2C, Power-to-Connector) airflow draws cool aisle air through the PSU side toward the port side, matching standard hot-aisle/cold-aisle layouts where the port side faces the hot aisle.
Deployment & Use Cases
Top-of-rack 100GbE leaf for AI/ML training clusters interconnecting NVIDIA GPU servers, RoCEv2 storage fabrics linking NVMe-oF arrays, leaf or aggregation switches in spine-leaf data center fabrics, bare-metal and disaggregated cloud infrastructure where ONIE flexibility is required, and high-density 25/50GbE access layers using QSFP28-to-SFP28 breakouts.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MSN2740-CB2F1O
Switch ASIC: Mellanox Spectrum
Port Configuration: 32 × QSFP28
Ethernet Speed per Port: 100GbE (downshift to 50/40/25/10GbE)
Form Factor: 1U
Chassis Depth: Short
Airflow: P2C (Forward, Power-to-Connector)
Power Supplies: 2 × AC, hot-swappable
Management CPU: x86
Pre-loaded OS: ONIE (no production NOS included)
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Compatible with NVIDIA Mellanox QSFP28 optics and cables (MMA1B00 SR4 transceivers, MMA1L10 LR4, MFA1A00 100GbE AOCs, MCP1600 100GbE DAC) and third-party QSFP28-compliant 100GbE optics. Compatible NICs include ConnectX-4 EN, ConnectX-5 EN and ConnectX-6 Dx EN at 100GbE. Rail kit is NOT included and must be ordered separately. The unit is Ethernet-only — it is not a VPI (InfiniBand-capable) switch. ONIE-loaded units do not include a Cumulus, Onyx, or SONiC license; OS licensing must be procured separately if required.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS performs port-by-port link verification, ASIC POST diagnostics, and PSU/fan validation on every Spectrum switch before shipment. Browse our full refurbished Mellanox catalog at https://www.tes-itsolutions.com. Standard handling time is 1–3 business days.