MSN3420-CB2FO - 48x25GbE 12x100GbE Spectrum-2 Switch | NVIDIA
MPN: MSN3420-CB2FO ✓ Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 5 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 25 | $0 | $0.00 |
| 50 | $0 | $0.00 |
MSN3420-CB2FO Overview
A data center Ethernet switch is a network device that forwards Layer-2 and Layer-3 traffic between servers, storage systems, and upstream networks. In the network hierarchy, a top-of-rack (ToR) switch like this one sits at the access layer, aggregating server connections and uplinking to leaf and spine switches in a fabric topology. Switches are classified as networking hardware rather than semiconductors, though the Spectrum-2 ASIC at their core performs packet processing in silicon.
Key features include wire-speed Layer-2 and Layer-3 forwarding for cloud-scale fabrics, port speeds spanning 1GbE to 100GbE on a single platform, Inband Network Telemetry (INT)-ready hardware, streaming telemetry support, and 512K on-chip flow counters for deep observability. The x86 onboard CPU allows full-featured network operating systems such as NVIDIA Onyx or Cumulus Linux via ONIE.
The Spectrum-2 ASIC is the second generation of NVIDIA's Spectrum switching silicon, purpose-built for leaf, spine, and super-spine data center applications with consistent low latency at full line rate.
Typical applications include top-of-rack server access for clouds migrating from 10G to 25G, leaf-spine fabric builds with 100GbE uplinks, and high-performance computing interconnects.
When deploying, confirm airflow direction (P2C on this SKU, C2P on the -CB2FC variant) matches rack cooling before ordering.
This page synthesizes distributor listings, sibling SKU comparisons, and deployment guidance not found in a single manufacturer document. Pricing data was not available in verified sources as of 2026-10-19; request a quote.
Drop-in alternatives for MSN3420-CB2FO — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MSN3420-CB2FO (same form factor and footprint) — differing in Airflow, Form Factor, Power Supplies, Product Type, Switching Capacity.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MSN3420-CB2FC
✅ Drop-In✓ In Stock
$16200 / Unit
View Datasheet →MSN3420-CB2F
✅ Drop-In📋 Reference alternative (not in catalog)
SSE-SN3420-CB2FC
✅ Drop-In📋 Reference alternative (not in catalog)
SSE-SN3420-CB2RC
✅ Drop-In📋 Reference alternative (not in catalog)
MSN3420-CB2FO Specifications (manufacturer-published)
| Product Type | Managed Layer-2/Layer-3 Open Ethernet switch |
| ASIC Family | NVIDIA Mellanox Spectrum-2 (SN3000 series) |
| SFP28 Ports | 48 x 25GbE (1/10/25GbE capable) |
| QSFP28 Ports | 12 x 100GbE (40/100GbE capable) |
| Total Port Count | 60 ports |
| Switching Capacity | 4.8 Tbps |
| Form Factor | 1U rack-mountable |
| CPU | x86 onboard |
| Boot Loader | ONIE (Open Network Install Environment) |
| Operating System | Open Ethernet (ONIE-compatible NOS; Onyx/Cumulus Linux supported on platform family) |
| Airflow | P2C (port-to-cloud, front-to-back) |
| Power Supplies | 2 x AC PSUs |
| Telemetry | Inband Network Telemetry (INT)-ready, Streaming Telemetry |
| Flow Counters | 512K on-chip flow counters |
| Target Deployment | Top-of-rack, leaf, spine, super-spine data center |
| Mounting | Rack-mountable (rail kit) |
MSN3420-CB2FO Interfaces & Connectors
No manufacturer-published interface list is available for MSN3420-CB2FO. Refer to the manufacturer documentation for connector and header details.
Refer to the manufacturer documentation for the full expansion header pinout and connector pin numbering.
Typical Applications
MSN3420-CB2FO is suitable for 6 applications: Top-of-Rack Server Access, Leaf-Spine Data Center Fabric, High-Performance Computing Interconnect, Cloud and Enterprise Data Center Aggregation, Storage Area Network Front-End, Out-of-Band and Management Networks.
Top-of-Rack Server Access
The MSN3420-CB2FO excels as a top-of-rack (ToR) switch for data centers migrating server connectivity from 10GbE to 25GbE. Its 48 SFP28 ports support 1/10/25GbE speeds, allowing a single ToR to serve mixed-speed server fleets during transition periods, while 12 QSFP28 ports provide 100GbE uplinks to the leaf or spine layer. With up to 4.8 Tbps of non-blocking Spectrum-2 switching capacity and wire-speed Layer-2/Layer-3 forwarding, it sustains full line rate under east-west traffic patterns typical of virtualized and containerized workloads. P2C airflow matches standard front-to-back server racks, and dual AC power supplies plus ONIE-based OS flexibility complete a rack-standard deployment. Deployed per rack, two units provide redundant server access with MLAG-style fabric designs supported by the platform family.
Recommended
Leaf-Spine Data Center Fabric
In a leaf-spine architecture, the MSN3420-CB2FO serves either role: as a leaf switch aggregating ToR uplinks at 100GbE, or as a spine switch connecting leaf layers via its 12 QSFP28 ports. The Spectrum-2 ASIC delivers consistent low latency at wire speed for Layer-2 and Layer-3 cloud-scale fabrics, which NVIDIA's SN3000 documentation identifies as a core design goal. INT-ready hardware, streaming telemetry, and 512K on-chip flow counters give operators per-flow visibility to detect microbursts, congestion, and elephant flows across the fabric. Combined with ONIE-installable network operating systems, the switch integrates into open fabrics built on Cumulus Linux, Onyx, or third-party NOS builds. Its 1U depth and dual AC supplies fit standard data center power and cooling envelopes.
Recommended
High-Performance Computing Interconnect
High-performance computing clusters benefit from the MSN3420-CB2FO's low-latency Spectrum-2 forwarding and high port density. HPC storage and parallel filesystem front-end networks commonly run 25GbE to compute nodes with 100GbE uplinks to storage services - precisely the port mix this switch provides. The platform's consistent low latency at full line rate, documented across the SN3000 series by NVIDIA, minimizes tail latency in allreduce-style east-west traffic. Flow counters and streaming telemetry help tune congestion across the fabric during job ramp-ups. Because the switch is Open Ethernet (ONIE), HPC sites can run the same NOS across vendor generations, simplifying operational consistency across mixed Mellanox/NVIDIA and third-party Spectrum deployments.
Recommended
Cloud and Enterprise Data Center Aggregation
For cloud providers and enterprise data centers, the MSN3420-CB2FO operates as an aggregation switch consolidating 25GbE access layers into 100GbE core links. Its 60-port configuration (48 SFP28 + 12 QSFP28) enables flexible blocking ratios - for example, 4:1 oversubscription or non-blocking designs depending on fiber planning. The Spectrum-2 ASIC supports port speeds from 1GbE to 400GbE across the SN3000 family, giving operators a growth path without forklift redesign. Layer-3 features including routing at wire speed support VXLAN-underlay and routed-overlay architectures common in modern cloud fabrics. Dual AC PSUs and the x86 CPU with ONIE provide the redundancy and OS openness enterprise procurement typically requires.
Recommended
Storage Area Network Front-End
Modern all-flash storage arrays and hyperconverged infrastructure expose 25GbE iSCSI, NVMe/TCP, or NVMe-oF front-end ports, making the MSN3420-CB2FO an ideal dedicated storage fabric switch. Its 48 SFP28 ports connect storage controllers and initiators at 25GbE, while QSFP28 uplinks attach storage services to the general fabric at 100GbE. The Spectrum-2 ASIC's consistent low latency and wire-speed forwarding protect I/O performance under heavy random-read workloads, where tail latency directly affects application response. On-chip flow counters isolate noisy-neighbor effects between storage tenants. With ONIE openness, storage administrators can standardize on their preferred network OS and telemetry stack, and dual AC supplies maintain fabric uptime during power events.
Recommended
Out-of-Band and Management Networks
The MSN3420-CB2FO also fits management and out-of-band (OOB) network roles in large deployments, where its 1/10/25GbE-capable SFP28 ports in dense 1U accommodate hundreds of management interfaces via breakout cables, and QSFP28 ports provide future-proof uplinks. The x86 CPU and ONIE boot loader allow lightweight open NOS images suited to management-plane duties, while streaming telemetry and 512K flow counters support monitoring infrastructure itself. Because the platform spans 1GbE to 400GbE across the SN3000 family, a management network built on this switch stays compatible with future generations of NVIDIA switching. P2C airflow and dual AC power suit standard rack deployment, and its wire-speed L2/L3 forwarding handles large ARP/ND tables in big clusters.
Recommended
Recommended Products Summary
Engineering reference data for MSN3420-CB2FO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MSN3420-CB2FC | MSN3420-CB2F | SSE-SN3420-CB2FC | SSE-SN3420-CB2RC |
|---|---|---|---|---|---|
| Brand | NVIDIA (Mellanox) | NVIDIA (Mellanox) | NVIDIA (Mellanox) | Supermicro | Supermicro |
| Package | 1U rack-mount switch system | 1U rack-mount switch system - same | 1U rack-mount switch system - same | 1U rack-mount switch system - same class | 1U rack-mount switch system - same class |
| SFP28 Ports (25GbE) | 48 | 48 | 48 | 48 | 48 |
| ASIC | Spectrum-2 (SN3000 series) | Spectrum-2 | Spectrum-2 | Spectrum-2 | Spectrum-2 |
| Lifecycle Status | Active (new and refurbished channels) | Active | Active | EOL / discontinued | EOL / discontinued |
Key Differentiators
- P2C airflow for standard front-to-back racks (vs MSN3420-CB2FC)
- ONIE open software flexibility (vs MSN3420-CB2F)
- Currently orderable vs discontinued cross-brand equivalents (vs SSE-SN3420-CB2FC)
Design Notes
Airflow direction is the most frequent ordering error on this platform. The MSN3420-CB2FO uses P2C (port-to-cloud, front-to-back) airflow; the MSN3420-CB2FC uses C2P. NVIDIA's SN3000 ordering documentation explicitly warns to pay attention to airflow direction when ordering. Deploying a C2P unit in a front-to-back rack (or vice versa) causes recirculation of hot exhaust air and eventual thermal throttling or shutdown. Verify rack cooling direction before placing the order, and label replacement units accordingly in your spares pool.
As a complete switch system, site preparation matters more than board layout: reserve 1U of rack space with front-to-back airflow, verify dual AC power feeds from independent PDUs for redundancy, and confirm rack depth accepts a standard-depth 1U chassis with the rail kit. Plan cabling so SFP28 DAC/AOC cables and QSFP28 uplinks do not obstruct the airflow exhaust side. Leave at least 1U of breathing space above and below when possible to help exhaust dissipation at full 4.8 Tbps traffic load.
At 25GbE per lane and 100GbE over 4 lanes, interconnect choice strongly affects link margins. Use DAC cables (e.g., MFS1S50 series) for in-rack links under 3 m, AOCs for mid-reach runs, and optical transceivers such as 100GBASE-SR4 or LR4 QSFP28 for longer spine links. Clean fiber end-faces before installation - contamination is the leading cause of 100G optical link flaps. Enable streaming telemetry and monitor the 512K on-chip flow counters to catch marginal links showing retransmits before they impact applications.
Compliance Information
Compliance declarations for complete switch systems are typically published by NVIDIA in product regulatory documentation; not present in the provided verified data.
