NVIDIA Mellanox MSN2420-CB2F Switch, 25GbE/100GbE, Onyx OS

NVIDIA Mellanox® MSN2420-CB2F — Spectrum 25/100GbE Half-Width Open Ethernet Leaf Switch

Technical Identity

The NVIDIA Mellanox® MSN2420-CB2F is a half-width 1U Open Ethernet leaf / Top-of-Rack switch built on the first-generation NVIDIA Spectrum™ ASIC. It provides 48× 25GbE SFP28 downlink ports and 4× 100GbE QSFP28 uplink ports in a compact half-19" chassis, delivering a non-blocking 2.0 Tb/s switching capacity with sub-microsecond ~300 ns port-to-port latency. The -CB2F suffix denotes Onyx (MLNX-OS) firmware pre-installed, two hot-swap power supplies (1+1 redundant), and forward (port-to-PSU / C2P) airflow — the standard cold-aisle intake configuration for hot-aisle/cold-aisle data center rows.

Specifications

• Manufacturer: NVIDIA Mellanox
• Part Number (MPN): MSN2420-CB2F
• Product Family: Spectrum SN2420 series
• Switch ASIC: NVIDIA Spectrum (1st generation)
• Port Configuration: 48× 25GbE SFP28 + 4× 100GbE QSFP28
• Switching Capacity: 2.0 Tb/s non-blocking
• Forwarding Rate: ~1.7 Bpps
• Port-to-Port Latency: ~300 ns (cut-through L2/L3)
• Packet Buffer: Fully shared, 16 MB on-chip
• Operating System: NVIDIA Onyx (MLNX-OS) pre-installed; Cumulus Linux and SONiC supported via ONIE
• Form Factor: Half-width 1U (two units fit side-by-side in a single 19" RU)
• Power Supplies: 2× hot-swap (1+1 redundant)
• Airflow: Forward (C2P — port-side intake → PSU-side exhaust)
• Management: Console (RJ45), USB, dedicated 1GbE OOB MGT port
• Protocol Support: Ethernet only (Spectrum ASIC — no InfiniBand)
• Condition: Refurbished Grade A — bench-tested by T.E.S IT-SOLUTIONS

What This Is NOT

• NOT an InfiniBand switch. The Spectrum ASIC is Ethernet-only — for IB fabrics use Quantum-family switches (SB7800, QM87xx, QM97xx).
• NOT a 200/400/800GbE switch. Maximum per-port speed is 100GbE (QSFP28). For higher-speed Ethernet uplinks see Spectrum-2 (SN3700) or Spectrum-3 (SN4700) platforms.
• NOT a full-width chassis. This is a half-width 1U — two MSN2420 units mount side-by-side in a single rack unit using the optional dual-mount kit.
• NOT supplied with transceivers, DACs, AOCs, or rail kit unless explicitly listed in the order.

Compatibility

• Compatible host adapters: ConnectX-4 / ConnectX-4 Lx, ConnectX-5 / ConnectX-5 Ex, ConnectX-6 / ConnectX-6 Dx, and ConnectX-7 NICs operating in Ethernet mode at 10/25GbE (SFP28 ports) or 40/100GbE (QSFP28 ports).
• Compatible interconnects: SFP28 25GbE DAC/AOC and optical transceivers on the 48 downlink ports; QSFP28 100GbE DAC/AOC, QSFP28 splitter cables (1× 100G → 4× 25G), and QSFP28 optical transceivers on the 4 uplink ports.
• Pairs upstream with: Spectrum-2 (SN3700) or Spectrum-3 (SN4700) 100/200/400GbE spine switches.
• Multi-vendor interop: Standards-based Ethernet — interoperates with Cisco Nexus, Arista 7000-series, Juniper QFX, Dell PowerSwitch, and HPE Aruba CX when running standard L2/L3 protocols.
• Software: Onyx (MLNX-OS) pre-installed; the switch is ONIE-enabled and accepts Cumulus Linux or SONiC as an alternative NOS.

FAQ

Q: What is the NVIDIA Mellanox MSN2420-CB2F?
A: It is a half-width 1U Spectrum-based Open Ethernet leaf switch with 48× 25GbE SFP28 ports and 4× 100GbE QSFP28 uplinks, pre-loaded with NVIDIA Onyx (MLNX-OS), equipped with dual redundant PSUs and forward (C2P) airflow.

Q: Does the MSN2420 support InfiniBand?
A: No. The Spectrum ASIC is Ethernet-only. For InfiniBand workloads use NVIDIA Quantum-family switches.

Q: Can I use the QSFP28 uplinks as 4× 25GbE breakouts?
A: Yes. Each of the 4 QSFP28 ports can be configured as a 4× 25GbE breakout using a QSFP28-to-4×SFP28 splitter, yielding up to 16 additional 25GbE ports.

Q: What does the -CB2F suffix mean?
A: C = Onyx (MLNX-OS) pre-installed, B = base feature set, 2 = two redundant power supplies, F = forward airflow (port-side intake to PSU-side exhaust).

Q: Is this unit compatible with non-NVIDIA equipment?
A: Yes — standards-based Ethernet with SFP28/QSFP28 MSA-compliant cages. Interoperates with Cisco, Arista, Juniper, Dell, and HPE switches and any standard SFP28/QSFP28 transceiver or DAC.

Q: What is the condition of this unit?
A: Refurbished Grade A. Each unit is bench-tested by T.E.S IT-SOLUTIONS: full port link validation, traffic verification on representative ports, PSU and fan health check, and cosmetic inspection.

Why T.E.S IT-SOLUTIONS

Every MSN2420-CB2F is bench-tested in our EU lab: link establishment across all 52 ports, PSU redundancy verification, fan-tray health, and Onyx boot validation. We ship from EU stock with anti-static packaging, and provide pre-sales technical consultation for Spectrum leaf-spine designs, NOS migration (Onyx → Cumulus / SONiC), and breakout-cable selection. See tes-itsolutions.com.