WS-C3850-24U-E Cisco Catalyst 3850 24 Ports UPOE IP Services

Product Overview

The Cisco WS-C3850-24U-E Catalyst 3850 is a high-performance, enterprise-grade Layer 3 managed Ethernet switch designed for scalable, secure, and power-efficient networks. Built for modern business environments, this switch delivers advanced routing, switching, and Universal Power over Ethernet (UPOE) capabilities, making it ideal for offices, campuses, and data-driven infrastructures.

General Specifications

Manufacturer & Model Details

• Brand: Cisco
• Model Number: WS-C3850-24U-E
• Product Line: Catalyst 3850 Series
• Device Category: Managed Network Switch

Form Factor & Design

• 24-port Ethernet switch with advanced Layer 3 support
• Stackable architecture for easy scalability
• Desktop-friendly and rack-mountable (1U) enclosure
• Gigabit Ethernet technology for high-speed connectivity

Port Configuration & Power Capabilities

Ethernet Ports

• 24 x 10/100/1000 Mbps Gigabit Ethernet ports
• Supports auto-negotiation and auto MDI/MDI-X

Power over Ethernet (PoE)

• Universal Power over Ethernet (UPOE) support
• High PoE budget of up to 800W
• Ideal for powering IP phones, wireless access points, and IoT devices

Performance & Scalability

Switching & Stacking Performance

• Switching capacity of up to 88 Gbps
• StackWise-480 technology with 480 Gbps stacking bandwidth
• Optimized for high-throughput enterprise networks

Capacity & Table Sizes

• IPv4 routing entries: up to 24,000
• NetFlow entries: 24,000
• Switched Virtual Interfaces (SVIs): up to 1,000
• MAC address table: 32,000 entries
• Jumbo frame support up to 9,198 bytes

Advanced Routing & Networking Protocols

Supported Routing Protocols

• BGP-4, IS-IS, RIP v1/v2
• EIGRP and EIGRP for IPv6
• OSPFv3, PIM-SM, PIM-SSM, RIPng

Layer 2 & Layer 3 Enhancements

• VLAN tagging and trunking support
• Layer 3 load balancing
• Virtual Routing and Forwarding Lite (VRF-Lite)
• IPv4 and IPv6 dual-stack support

Security & Control Features

• Access Control Lists (ACLs)
• RADIUS authentication support
• DHCP snooping and Dynamic ARP Inspection (DAI)
• IGMP and MLD snooping
• STP Root Guard and Uni-directional Link Detection (UDLD)

Traffic Optimization & QoS

• Quality of Service (QoS) for traffic prioritization
• Shaped Round Robin (SRR) scheduling
• Link Aggregation with LACP and PAgP
• Remote SPAN (RSPAN) for traffic analysis

Standards Compliance & Energy Efficiency

Industry Standards

• IEEE 802.3, 802.3u, 802.3ab, 802.3z
• IEEE 802.1D, 802.1Q, 802.1P, 802.1W, 802.1S, 802.1X
• IEEE 802.3af and 802.3at PoE standards

Energy & Power Specifications

• AC power input: 120/230V, 50/60Hz
• Optional power redundancy for high availability
• Energy Efficient Ethernet for reduced power consumption
• Cisco StackPower technology for flexible power sharing

Cisco Catalyst 3850 Series: The Foundation of Unified Access

The Cisco Catalyst 3850 Series represents a pivotal advancement in campus networking, converging wired and wireless services onto a single platform. At the heart of this series lies the innovative Cisco Unified Access Data Plane (UADP) application-specific integrated circuit (ASIC), which delivers consistent policy enforcement, application visibility, and performance whether clients connect via an Ethernet cable or a wireless access point. The Cisco WS-C3850-24U-E Catalyst 3850 24 Ports Ethernet Switch is a specific, powerful model within this acclaimed family, designed for the access layer where users and devices initially join the network. This 24-port, full Power over Ethernet (PoE+) model is engineered to support the most demanding environments, from enterprise offices and classrooms to healthcare rooms and smart buildings, providing the intelligence, resilience, and scalability required for modern digital business.

Deep Dive: The WS-C3850-24U-E Model Specifications

This specific SKU, the WS-C3850-24U-E, is configured for maximum flexibility and power delivery. It ships with the IP Base feature set, offering robust Layer 3 routing functionality, and is designed for network edge deployments. Understanding its core hardware specifications is key to evaluating its fit for your infrastructure.

Hardware Architecture & Performance

The switch is built around the UADP ASIC, which provides wire-rate switching and routing across all ports. It features a stacking bandwidth of 480 Gbps using the Cisco StackWise-480 technology, creating a virtual, single switching unit from up to 9 switches. The device includes a 4x10G SFP+ uplink module slot for high-speed connectivity to the network core or aggregation layer. With a total PoE+ budget of 600 watts, it can deliver up to 30 watts per port (IEEE 802.3at PoE+) to power a wide array of devices simultaneously.

Unified Access and Converged Management

A cornerstone of the Catalyst 3850's value proposition is its unified nature. Unlike traditional access switches that operate independently from the wireless LAN controller, the 3850 integrates a fully functional wireless LAN controller within the switch's IOS XE operating system. This convergence simplifies network architecture, reduces the number of devices to manage, and provides a single point of policy creation for both wired and wireless clients.

Benefits of the Embedded Wireless Controller

The embedded wireless controller can manage up to 50 Cisco Aironet access points directly, scaling with stack members. This capability makes the WS-C3850-24U-E an ideal choice for branch offices or campus floors where a separate physical wireless controller would be cost-prohibitive or operationally complex. It supports advanced features like CleanAir RF spectrum intelligence, Application Visibility and Control (AVC), and Cisco's High Density Experience (HDX) for challenging RF environments.

Simplified Operations with Cisco DNA Center

While manageable via CLI and traditional GUI, the Catalyst 3850 is fully compatible with Cisco Digital Network Architecture (DNA) Center. This allows for intent-based networking, where administrators can define business policies that are automatically translated and enforced across the network. Features like automated device provisioning, software image management, and advanced analytics for troubleshooting are centralized, dramatically reducing operational overhead.

Advanced Features for a Secure, Programmable Network

The WS-C3850-24U-E is far more than a simple connectivity box. It is packed with enterprise-grade features for security, quality of service (QoS), and application intelligence, all programmable via open APIs.

Comprehensive Security Posture

Security is embedded at multiple layers. The switch supports TrustSec technology for software-defined segmentation, using Security Group Tags (SGTs) to enforce policies regardless of IP address. It offers robust access control with 802.1X, MAC Authentication Bypass (MAB), and Web Authentication. Integrated threat defense includes features like Control Plane Policing (CoPP), DHCP snooping, Dynamic ARP Inspection (DAI), and IP Source Guard to protect against malicious traffic and attacks.

Application Intelligence with Cisco AVC and Flexible NetFlow

The switch provides deep application visibility through Application Visibility and Control (AVC), which uses NetFlow and NBAR2 to identify and classify over 1000 applications. Network administrators can create QoS policies to prioritize business-critical applications (like VoIP or video conferencing) and limit bandwidth for non-essential traffic. This ensures optimal user experience and efficient bandwidth utilization.

High Availability and Resiliency

For mission-critical operations, the switch offers multiple high-availability mechanisms. StackWise-480 creates a logical single switch, allowing for single IP management and hitless failover if a member switch fails. Features like Ethernet Ring Protection (REP), FlexLinks, and dual redundant power supply options (on specific models) ensure non-stop network operation.

Ideal Deployment Scenarios for the WS-C3850-24U-E

Understanding where this switch excels helps in making an informed purchasing decision. Its combination of high PoE budget, 10G uplink readiness, and unified access makes it suitable for several key environments.

Enterprise Branch or Campus Access Layer

This is the primary deployment scenario. As an access layer switch, it connects end-users, IP phones, and wireless access points. The 600W PoE budget can easily support a dense deployment of phones, video conferencing units, and 802.11ac Wave 2 access points that require standard PoE+.

Digital Buildings and IoT Convergence

With the proliferation of IoT devices—from smart lighting and HVAC controllers to security cameras and digital signage—the need for reliable PoE and secure segmentation is critical. The 3850's high port density, PoE capability, and TrustSec segmentation make it an excellent platform for converging building management systems onto the IT network.

Mid-Sized Business Core

For smaller to mid-sized organizations, a stack of Catalyst 3850 switches can serve as both the access and the core/distribution layer. The robust Layer 3 routing capabilities of the IP Base image, combined with high stacking bandwidth, can provide a simple yet powerful network backbone.

Software & Licensing: Understanding the "E" in WS-C3850-24U-E

The suffix in the model number is crucial. The "-E" denotes that this switch is equipped with the IP Base software image. Cisco's licensing for the Catalyst 3850 series typically follows a tiered model: LAN Base (basic Layer 2), IP Base (advanced Layer 3 routing like EIGRP stub, OSPF, PIM), and IP Services (full enterprise routing including BGP). The IP Base tier in this model provides more than sufficient routing protocols for most access and distribution layer deployments. It's important to note that software subscriptions for DNA Center features like Software-Defined Access (SD-Access) and Cisco AI Endpoint Analytics are separate and provide access to the latest innovation on the hardware platform.

Comparing the 24U-E: Key Differentiators and Alternatives

When selecting a switch, it's helpful to compare this model against others in its family and competitive offerings.

Within the Catalyst 3850 Family

The "24U" model specifically offers 24 PoE+ ports. Alternatives include the WS-C3850-24T (24 data-only ports), the WS-C3850-48U (48 PoE+ ports), and the WS-C3850-24U-S (with a 440W PoE budget). The "-E" (IP Base) can be compared to the "-L" (LAN Base) for simpler Layer 2 deployments. Choosing the 24U-E is the decision for a high-power, feature-rich access layer with future-proof 10G uplinks.

Against Successor Platforms (Catalyst 9000)

Cisco's next-generation Catalyst 9000 series (e.g., C9300) offers higher performance, greater programmability with a container-based IOS XE, and is the flagship for Cisco's SD-Access solution. The Catalyst 3850 remains a supremely capable and cost-effective workhorse, especially for environments not immediately transitioning to a full intent-based network model. For many, the 3850 represents an optimal balance of performance, features, and total cost of ownership.

Performance and Buffering

The switch utilizes a shared buffer architecture optimized for unified traffic patterns. It supports jumbo frames up to 9198 bytes and features advanced queueing mechanisms (8 queues per port) for precise QoS treatment. The 176 Gbps switching capacity ensures no internal blocking across all 24 Gigabit ports and the 40 Gbps of potential uplink bandwidth.

Management and Programmability

Management interfaces include a dedicated RJ-45 console port, a dedicated MGMT port, and a USB console port. The switch is programmable via RESTful APIs, Python scripts, and supports Model-Driven Programmability (MDP) with YANG data models. This programmability enables automation and integration with IT workflow tools, paving the way for DevOps-style network operations.