P17521-001 HPE SN3700cM 100GbE QSFP28 Layer 3 32 Ports Managed Switch

HPE P17521-001 SN3700cM 32 Ports Managed Switch

The HPE SN3700c series represents a pinnacle of high-performance, high-density 100 Gigabit Ethernet switching, engineered for the most demanding modern data center environments. As a critical component of Hewlett Packard Enterprise's Composable Fabric portfolio, these switches are built to deliver exceptional throughput, ultra-low latency, and the flexibility required for scalable, software-defined infrastructure. The specific model, HPE P17521-001 SN3700cM, stands out as a fully managed, 1U rack-mountable switch designed to act as a high-performance leaf or spine node in web-scale, cloud, and enterprise data centers.

Core Architecture and Performance Specifications

At the heart of the SN3700cM is a cutting-edge switching ASIC, capable of handling immense data loads with deterministic performance. The switch is engineered for non-blocking, line-rate throughput across all ports simultaneously, ensuring that performance is never compromised under full load. This makes it an ideal solution for data-intensive applications, high-performance computing (HPC) clusters, and large-scale storage backends.

Port Density and Interface Details

The hallmark of the HPE P17521-001 is its impressive port configuration. It comes equipped with 32 fixed ports of 100 Gigabit Ethernet, presented in the QSFP28 form factor. This high-density design allows for a massive aggregation of server and storage connections within a single rack unit, maximizing space and power efficiency in the data center.

QSFP28 Versatility and Breakout Capabilities

The use of QSFP28 (Quad Small Form-factor Pluggable 28) transceivers is a key feature. These ports are not limited to 100GbE connections; they offer significant flexibility through breakout cabling. Each QSFP28 port can be broken out into:

• • 4 independent 25 Gigabit Ethernet (25GbE) connections using a QSFP28 to 4x SFP28 cable or breakout module.
• • This effectively transforms the switch from a 32-port 100GbE device into a 128-port 25GbE switch, providing granular connectivity for high-density server racks without sacrificing bandwidth.

This breakout functionality is crucial for supporting modern servers equipped with 25GbE network interfaces, allowing for a cost-effective and streamlined cabling infrastructure while preserving the option for 100GbE uplinks or storage connectivity.

Layer 3 Routing and Protocol Support

As a fully managed Layer 3 switch, the SN3700cM provides advanced routing capabilities directly within the switching fabric. It supports a comprehensive suite of dynamic routing protocols, enabling it to operate seamlessly in complex, multi-subnet environments.

Dynamic Routing Protocols

The switch supports Border Gateway Protocol (BGP) for large-scale data center and internet peering, Open Shortest Path First (OSPF) for efficient interior gateway routing, and Protocol Independent Multicast (PIM) for optimized multicast traffic distribution. This extensive protocol support allows the switch to function as a true routing node, collapsing traditional network tiers and reducing latency by keeping traffic forwarding decisions within the switch hardware.

Form Factor and Physical Design

The 1U rack-mountable design is optimized for standard 19-inch equipment racks. This compact form factor allows for efficient use of valuable data center real estate. The switch features a robust, metal chassis built for continuous operation in demanding environments.

Airflow Configuration: Port-Side Exhaust

The "M" suffix in the SN3700cM model number denotes a specific airflow direction, which is a critical consideration in modern data center cooling design. This model is configured for port-side exhaust airflow. This means the switch draws cool air from the cold aisle (typically the front or non-port side of the rack) and exhausts heated air out through the ports into the hot aisle. It is imperative to match the switch's airflow direction (marked on the device) with the data center's hot aisle/cold aisle containment strategy to prevent overheating and ensure optimal cooling efficiency.

Advanced Management

Beyond traditional switch management, the SN3700cM is built for the era of software-defined networking and infrastructure as code. It offers multiple management paradigms to suit different operational models.

HPE Composable Fabric Integration

This switch is a native component of the HPE Composable Fabric solution. When used within this framework, it can be managed as part of a unified, software-defined network fabric. Composable Fabric provides centralized management, automated provisioning, and a single pane of glass for monitoring the entire network, transforming physical infrastructure into a programmable, policy-driven resource pool.

Traditional CLI and Web Interface

For conventional network management, the switch is accessible via a detailed Command Line Interface (CLI) modeled on industry-standard syntax. It also offers an intuitive web-based graphical user interface (GUI) for day-to-day monitoring and configuration tasks, making it accessible to administrators with varying levels of expertise.

Key Features for Modern Data Centers

The SN3700cM is packed with features that address the specific challenges of cloud, hyper-scale, and enterprise data center operations.

Virtualization and Network Segmentation

The switch supports a large number of VLANs (Virtual Local Area Networks) and VXLAN (Virtual Extensible LAN) gateways. VXLAN support is particularly important for creating overlay networks that span across physical Layer 3 boundaries, enabling massive multi-tenancy and seamless workload mobility in virtualized and cloud environments.

Buffer Capacity

Engineered for data center workloads, the switch is equipped with a deep packet buffer. This is essential for handling transient traffic bursts, common in east-west data center traffic patterns, without incurring packet drops. This ensures smooth performance for storage traffic, Hadoop/Spark clusters, and other burst-sensitive applications.

Reliability and Availability

Designed for always-on operations, the SN3700cM incorporates several features to maximize uptime and simplify maintenance.

Redundant and Hot-Swappable Components

The switch is typically equipped with hot-swappable, redundant power supplies and fan trays. This design allows for the replacement of failed power or cooling components without powering down the switch, enabling maintenance with zero network downtime. The specific power supply configurations (AC or DC) may vary based on the ordered model.

Link Aggregation and Failover

It supports various link aggregation protocols, including Link Aggregation Control Protocol (LACP), allowing multiple physical links to be bonded into a single, logical, higher-bandwidth connection. This provides both increased throughput and inherent link-level redundancy; if one physical link fails, traffic is automatically redistributed across the remaining active links.

Use Cases and Application Scenarios

The versatility of the HPE SN3700cM makes it suitable for a wide array of demanding networking roles.

Leaf Switch in a Spine-Leaf (Clos) Architecture

This is its primary design role. As a leaf switch, it provides high-density 25GbE or 100GbE connectivity to servers, storage arrays, and appliances within a rack or row. Its Layer 3 capabilities allow for efficient any-to-any connectivity through the spine layer, minimizing latency and eliminating network bottlenecks.

High-Performance Compute (HPC)

The combination of ultra-low latency, high bandwidth, and support for RoCE (RDMA over Converged Ethernet) makes this switch ideal for HPC clusters and artificial intelligence/machine learning training environments. These applications require massive, parallel data exchanges between nodes, and the non-blocking architecture of the SN3700cM ensures that the network does not become a bottleneck.

Massive Scale Storage Backend

For scale-out storage platforms like Isilon, Elastic Storage Server, or other NAS/SDS solutions, the switch provides the high-bandwidth, low-latency fabric necessary to connect storage nodes and ensure fast data access for clients and applications. The deep buffers are particularly beneficial in handling large, sequential storage read/write operations.

Data Center Interconnect (DCI)

With its 100GbE ports and advanced routing capabilities, the switch can be effectively used to interconnect multiple data centers over dark fiber or leased lines, creating a high-bandwidth, stretched fabric for disaster recovery and workload mobility.