NVIDIA Mellanox MSN3700-CS2FC Spectrum-2 1U Open Ethernet Switch, 32× QSFP28 with Cumulus Linux: This is a 1U fixed-port Open Ethernet switch built on the NVIDIA Spectrum-2 ASIC. It provides 32 ports of QSFP28 supporting 100GbE and 40GbE, with 4×25GbE / 4×10GbE breakout per port. The CS2FC variant ships with Cumulus Linux preinstalled and uses P2C (power-to-connector) airflow. This is not a modular chassis switch. The trailing C in the part number indicates the Cumulus Linux preload — a refurbished unit may require relicensing of Cumulus from NVIDIA for production support. This is a refurbished unit.
Engineering Context
The MSN3700-CS2FC is a Spectrum-2 platform delivering 6.4 Tbps of switching capacity from 32 QSFP28 ports running at 100GbE line rate, with port-to-port latency in the ~300 ns range typical of Spectrum-2 silicon. Each QSFP28 port can be split into 4×25GbE or 4×10GbE for high-density access aggregation, giving up to 128 logical 25GbE ports per 1U chassis. Cumulus Linux on Spectrum-2 supports BGP-EVPN, VXLAN routing, NetQ telemetry, and Linux-native automation tooling (Ansible, ZTP, Puppet). Dual hot-swappable PSUs and N+1 fan redundancy are standard. Spectrum-2 hardware accelerates RoCE v2 with ECN and PFC for lossless storage and AI fabrics.
Deployment & Use Cases
Spine and aggregation switching in 100GbE spine-leaf data center fabrics. Cumulus-standard environments where the operations team has existing Linux/Ansible automation. AI/ML cluster fabrics for GPU compute nodes requiring RoCE v2. NVMe-oF and software-defined storage backbones. Service provider edge POPs running BGP-EVPN with VXLAN. Replacement of legacy Cumulus-based 40/100GbE switches in established NetDevOps shops.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MSN3700-CS2FC
Switch ASIC: NVIDIA Spectrum-2
Form Factor: 1U fixed-port rack switch
Ports: 32× QSFP28 (40/100GbE)
Breakout: 4× 25GbE or 4× 10GbE per QSFP28
Switching Capacity: 6.4 Tbps
Port-to-Port Latency: ~300 ns
Software: Cumulus Linux preloaded
Airflow: P2C (Forward) — PSU-side intake, port-side exhaust
Power Supplies: Dual hot-swappable redundant AC PSUs
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
The MSN3700-CS2FC is an Ethernet-only switch — it is not a VPI device and does not support InfiniBand. QSFP28 cages accept QSFP28 and QSFP+ optics/AOCs/DACs at compatible speeds; SFP-form modules are not supported without a QSA adapter. Breakout requires supported breakout cables (QSFP28 to 4×SFP28). Cumulus Linux on a refurbished unit may not include current vendor support entitlements; production deployments that require NVIDIA Cumulus support should plan to relicense or migrate to SONiC/Onyx. The P2C airflow direction must match the rack's hot/cold aisle layout — installing in a C2P-airflow rack will cause hot-air recirculation.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS power-tests every Spectrum-2 switch, verifies port LED status across all 32 QSFP28 cages, confirms Cumulus Linux boot, and checks airflow direction before shipment. Visit tes-itsolutions.com for expert consultation on Spectrum-2 fabric design, Cumulus licensing options, global shipping with 1–3 day handling, and warranty coverage on every unit.