C1-N9K-C93120TX Cisco ONE Nexus 9000 Switch

Product Overview

The Cisco C1-N9K-C93120TX ONE Nexus 9000 Series Switch is a high-performance Layer 3 networking solution designed for modern data centers. Built to deliver reliability, scalability, and advanced switching capabilities, this enterprise-grade switch supports demanding workloads and high-speed connectivity requirements.

General Product Information

• Manufacturer Part Number: C1-N9K-C93120TX
• Brand Name: Cisco
• Product Type: Layer 3 Network Switch
• Product Line: Nexus
• Series: 9300
• Model: 93120TX

Port Configuration and Expansion Options

The Cisco Nexus 93120TX switch offers extensive port density and flexible expansion, making it ideal for high-throughput networking environments.

Network Port Details

• Total Network Ports: 96 × 10 Gigabit Ethernet
• High-speed connectivity for servers and storage

Expansion Capabilities

• Expansion Slots: 6 × 40 Gigabit Ethernet QSFP+
• Modular Design: Yes
• Stack Port: Not available

Key Highlights of Cisco Nexus 93120TX

• Enterprise-class Layer 3 switching capabilities
• High-density 10 Gigabit Ethernet ports
• Expandable architecture for future growth
• Optimized for data center and cloud environments

Performance and Media Compatibility

Designed for optimal performance, this Cisco Nexus switch supports multiple media types and advanced Ethernet technologies to ensure seamless data transmission.

Supported Media Types

• Optical Fiber
• Twisted Pair Cabling

Networking and Ethernet Technologies

• 10 Gigabit Ethernet
• 40 Gigabit Ethernet
• 10GBase-T
• 40GBase-X

Layer Support and Management Features

With full Layer 3 support and advanced management capabilities, the Cisco Nexus 93120TX enhances network control, security, and performance optimization.

Layer and Management Details

• Supported Layer: Layer 3
• Manageable: Yes
• Ideal for complex routing and switching tasks

Power and Reliability

The switch is powered by a dedicated power supply, ensuring stable and continuous operation in mission-critical environments.

• Power Source: Power Supply
• Designed for data center-grade reliability

Cisco ONE Nexus 9000 Series Switches

The Cisco Nexus 9000 Series, particularly the Cisco C1-N9K-C93120TX, represents the pinnacle of data center switching technology. Designed to operate in both traditional NX-OS and modern Application-Centric Infrastructure (ACI) modes, this series delivers unmatched flexibility, performance, and scalability. As businesses undergo digital transformation, the underlying network must evolve from a static, hardware-centric model to a dynamic, software-driven fabric that supports cloud agility, operational simplicity, and robust security. The 93120TX model is a cornerstone of this evolution, specifically engineered to bridge the gap between high-density 10 Gigabit Ethernet over copper (10GBASE-T) access and high-speed 40/100 Gigabit uplink requirements, making it an ideal choice for top-of-rack (ToR) and middle-of-row deployments.

Key Specifications and Architecture of the C1-N9K-C93120TX

At its core, the Nexus 93120TX is a 2-Rack-Unit (2RU) fixed-port switch built on Cisco's cloud-scale ASIC technology. This architecture delivers consistent, low-latency performance and rich feature sets crucial for today's dynamic workloads.

Port Configuration and Density

The switch's physical design is optimized for data center efficiency, offering a balanced and future-ready port layout.

Access Ports: 48 x 10GBASE-T RJ-45

This dense array of 10 Gigabit Ethernet ports supports the widespread adoption of servers equipped with 10Gb copper network interface cards (NICs). The use of standard RJ-45 connectors simplifies cabling, reduces costs compared to fiber SFP+ optics, and eases migrations from older 1GbE infrastructures. These ports offer auto-negotiation down to 100Mbps, providing exceptional backward compatibility.

Uplink Ports: 6 x QSFP28

For upstream connectivity and spine-layer aggregation, the switch provides six high-speed QSFP28 ports. Each port can operate as a native 40GbE or 100GbE interface. Furthermore, using breakout cables, each QSFP28 port can be split into 4x 10GbE or 4x 25GbE connections, offering tremendous design flexibility. This allows for a versatile spine-and-leaf topology, enabling high-performance East-West traffic flows within the data center.

Performance and Throughput

The switch is engineered for non-blocking performance. With a high-bandwidth switching capacity of up to 3.6 Tbps, it ensures that all ports can operate at line rate simultaneously, preventing congestion and bottlenecks. This is critical for bandwidth-intensive applications like big data analytics, virtualized environments, and storage networking.

Deployment Flexibility: NX-OS Mode vs. ACI Mode

A defining characteristic of the Nexus 9000 series, including the 93120TX, is its operational duality. Customers can choose the software image that aligns with their network strategy, with the option to transition between modes as needs evolve.

Cisco NX-OS: The Proven, Feature-Rich Standalone Mode

When deployed with the standalone NX-OS software, the switch operates as a high-performance, mission-critical Ethernet switch. It leverages the mature, battle-tested NX-OS operating system, known for its stability, comprehensive feature set, and modularity. Key capabilities in this mode include:

Virtual Extensible LAN (VXLAN) Routing & Bridging: Enables the creation of large-scale, multi-tenant Layer 2 and Layer 3 overlay networks, extending networks across physical boundaries for cloud architectures.
Advanced Routing Protocols: Full support for BGP, OSPF, EIGRP, and PBR (Policy-Based Routing) for robust Layer 3 underlay networks.
Comprehensive Security: Features like ACLs, TrustSec, CoPP, and port security provide granular control and threat mitigation.
High Availability: In-service software upgrades (ISSU), Graceful Insertion and Removal (GIR), and redundant power/control plane components ensure maximum uptime.

Cisco ACI: The Revolutionary Policy-Driven Fabric Mode

When deployed as part of an Application Centric Infrastructure (ACI) fabric, the switch transforms from a standalone device into an intelligent node within a software-defined network. ACI abstracts network policies from the physical hardware, allowing administrators to define application requirements in a centralized policy model.

Intent-Based Networking: Administrators declare *what* the application needs (e.g., "Application A can talk to Database B on port 3306"), and the ACI fabric automatically translates this intent into network configurations.
Centralized Management with APIC: The fabric is managed by the Application Policy Infrastructure Controller (APIC), providing a single pane of glass for policy, health monitoring, and troubleshooting.
Integrated Security with Micro-Segmentation: ACI enables granular security policies at the workload level, regardless of the workload's location (physical, virtual, or cloud), dramatically reducing the attack surface.

Advanced Features and Technologies

Beyond its basic switching functions, the Nexus 93120TX is packed with advanced technologies designed for modern data center challenges.

Automation and Programmability

The switch is built for network automation, featuring:

Open APIs: Full support for RESTful APIs, allowing for integration with DevOps tools and custom automation scripts.
Support for Ansible, Puppet, and Chef: Infrastructure-as-Code (IaC) tools can be used to provision, configure, and manage the switch consistently and at scale.
Python and Guest Shell: An on-switch Linux environment (Guest Shell) allows for the execution of custom Python scripts directly on the device for localized automation and data collection.
Model-Driven Programmability (YANG, NETCONF, gRPC): Supports modern, model-driven interfaces for streaming telemetry and structured configuration management.

High Availability and Resiliency

Data center operations demand maximum uptime. The 93120TX is designed with several resiliency features:

Redundant, Hot-Swappable Power Supplies and Fans: Minimizes downtime due to component failure. Options include AC and DC power supplies.
ISSU and EPLD Upgrades: Allows for software and firmware upgrades without a full system reboot, maintaining network availability.
Port-Channel Technologies (vPC, LACP): Provides link-level redundancy and increased bandwidth through the aggregation of multiple physical links into a single logical channel. Virtual Port-Channel (vPC) eliminates the Spanning Tree Protocol (STP) blocked-port scenario, allowing all uplinks to be active.

Ideal Use Cases and Applications

The specific design of the Cisco C1-N9K-C93120TX makes it exceptionally well-suited for several critical data center roles.

High-Density 10GbE Top-of-Rack (ToR) Deployment

This is the primary use case. The switch connects directly to a rack of servers with 10GbE NICs, providing cost-effective, high-bandwidth access. Its 10GBASE-T ports eliminate the need for expensive SFP+ transceivers, using standard Cat6a/Cat7 cabling. The high-speed QSFP28 uplinks then connect to the data center spine layer, ensuring no oversubscription and optimal performance.

Middleware or End-of-Row (EoR) Aggregation

In larger deployments, the switch can aggregate traffic from multiple racks of 1GbE or 10GbE switches, acting as a high-performance aggregation node. Its deep buffers and high throughput manage traffic bursts effectively, preventing packet loss.

Converged Storage and Data Networks

With support for Data Center Bridging (DCB) standards like Priority Flow Control (PFC) and Enhanced Transmission Selection (ETS), the 93120TX can seamlessly converge traditional IP traffic with storage protocols like Fibre Channel over Ethernet (FCoE), simplifying cabling and reducing capital expenditure.

Building Blocks for Private and Hybrid Cloud

Whether in NX-OS mode with VXLAN EVPN or as an ACI leaf node, this switch is a fundamental building block for creating scalable, secure, and automated private cloud infrastructures. Its programmability and policy-enforcement capabilities are essential for supporting agile development and operations (DevOps).