WS-C3850-12X48U-L Cisco Catalyst Ethernet Switch

Product Outline

The Cisco WS-C3850-12X48U-L Catalyst 3850 is a high-performance, enterprise-grade managed network switch designed to deliver reliable connectivity, advanced Layer 3 routing, and scalable switching for modern business environments. With 48 Gigabit Ethernet ports and Cisco StackWise technology, this switch is ideal for campus networks, data centers, and growing enterprises seeking stability, security, and future-ready performance.

General Specifications

Manufacturer and Model Details

• Brand: Cisco
• Part Number: WS-C3850-12X48U-L
• Device Category: Managed Layer 3 Ethernet Switch
• Form Factor: Desktop or 1U Rack-Mountable
• Switch Type: Stackable Gigabit Ethernet Switch

Port Configuration and PoE Capabilities

High-Density Connectivity

• 48 × 10/100/1000 Mbps Ethernet ports
• Supports Universal Power over Ethernet (UPOE)
• Ideal for IP phones, wireless access points, and IoT devices

Power over Ethernet Details

• PoE Technology: UPOE
• Total PoE Budget: 630 Watts
• Efficient power delivery for high-demand network devices

Performance and Switching Capacity

Enterprise-Class Throughput

• Switching Capacity: 176 Gbps
• Stacking Bandwidth: 480 Gbps
• Forwarding Rate: 460 Mpps (64-byte packets)

Scalability and Network Capacity

• IPv4 routing entries: up to 24,000
• NetFlow records: up to 48,000 entries
• Switched Virtual Interfaces (SVIs): up to 1,000
• MAC address table: 32,000 entries
• Jumbo frame support: up to 9,198 bytes

Routing and Management Protocols

Advanced Layer 3 Routing

• RIP v1 and v2
• EIGRP
• RIPng for IPv6

Advanced Networking Features

Security, Reliability, and Optimization

• VLAN and trunking support
• Access Control Lists (ACL)
• Quality of Service (QoS)
• DHCP Snooping and Dynamic ARP Inspection (DAI)
• IGMP and MLD Snooping
• IPv4 and IPv6 compatibility
• Rapid Spanning Tree (RSTP), MSTP, and PVST+
• Link Aggregation with LACP and PAgP
• Energy Efficient Ethernet technology

Cisco Exclusive Technologies

• Cisco StackWise-480 for high-speed stacking
• Cisco StackPower for power sharing and redundancy
• Flexible NetFlow (FNF) for traffic analysis
• VRF-Lite for network segmentation

Standards and Compliance

Industry-Recognized Protocols

• IEEE 802.3, 802.3u, 802.3z
• IEEE 802.1Q, 802.1P, 802.1D
• IEEE 802.3af and 802.3at (PoE standards)
• IEEE 802.1X, 802.1W, 802.1S
• IEEE 802.3ad (LACP)

Power and Reliability

Efficient and Redundant Power Design

• AC input: 120/230V, 50–60 Hz
• Optional power redundancy for high availability
• Designed for continuous enterprise operation

Architectural Superiority and Core Features

At the heart of the Catalyst 3850 lies Cisco's StackWise-480 technology and the unified IOS XE operating system, creating a foundation that is both powerful and adaptable to evolving business needs.

StackWise-480 Technology: Unmatched Resiliency and Scalability

Unlike traditional standalone switches, the WS-C3850-12X48U-L is designed to operate as part of a logical, single-entity stack.

High-Bandwidth Stacking Ring

The StackWise-480 backplane creates a 480 Gbps bidirectional ring for inter-switch communication, ensuring that bandwidth is never a bottleneck for control or data traffic between stack members.

Single-Point of Management

An entire stack of up to nine switches is managed as one device—one IP address, one configuration file, and one software image—dramatically simplifying provisioning, troubleshooting, and policy enforcement across the network edge.

Hitless Failover and Stateful Switchover

In a stack, if the master switch fails, a subordinate switch assumes the master role within seconds without dropping user sessions, ensuring continuous network availability for critical applications.

Unified IOS XE Operating System

This modern operating system provides a consistent feature set and management interface across the Cisco portfolio, from access switches to enterprise routers.

Programmability and Automation

IOS XE supports open APIs, Python scripting, and model-driven programmability, enabling network automation for tasks like zero-touch provisioning, consistent policy deployment, and streamlined operational workflows.

Enhanced Stability and Serviceability

Its modular design allows for in-service software upgrades (ISSU) and patching, minimizing downtime during maintenance windows and improving overall network stability.

Detailed Port Configuration and Power Capabilities

The "12X48U-L" designation is key to understanding this switch's physical capabilities. It is engineered to support a high-density, power-rich environment typical of modern workspaces.

48-Port Main Switching Board

The switch offers 48 downlink ports of extreme flexibility.

Multigigabit Ethernet (mGig)

All 48 ports are Ethernet ports that automatically sense and support speeds from 100Mbps and 1Gbps up to 2.5Gbps and 5Gbps (on mGig-capable models, with the U variant being a key identifier), preparing your network for next-generation 802.11ac Wave 2 and Wi-Fi 6/6E access points that require beyond 1Gbps uplinks.

Full PoE/PoE+ Capability

Each of the 48 ports can deliver IEEE 802.3af (PoE) or 802.3at (PoE+) power, enabling the simultaneous connection and powering of a vast array of devices such as IP phones, wireless access points, video surveillance cameras, and IoT sensors.

Integrated Power Supply and Uplinks

The switch includes a fixed, high-capacity power supply and flexible uplink options.

1150W AC Power Supply

The integrated 1150W power supply provides substantial power budgets for full PoE+ across all ports, supporting the most demanding power-over-Ethernet deployments without requiring external power injectors.

Network Module Uplink Slots

The switch features four dedicated uplink slots that accept a variety of Cisco network modules, allowing for customizable uplink connectivity. Options include 1G, 10G, and 40G Ethernet modules, providing the flexibility to scale uplink bandwidth as network demands grow.

Converged Access and Wireless LAN Controller Functionality

This is the defining innovation of the Catalyst 3850 series. It integrates an embedded wireless LAN controller (WLC), eliminating the need for a separate physical or virtual WLC appliance for small to medium-sized deployments.

Unified Wired and Wireless Policy

With the converged access model, policies for security, quality of service (QoS), and access control are defined once and apply seamlessly to any device, regardless of its entry point into the network.

Consistent Access Control

Leveraging technologies like Cisco TrustSec and Identity Services Engine (ISE) integration, a user's permissions follow them from a wired desktop to a wireless laptop, ensuring compliance and security.

Unified QoS

Voice and video traffic receive appropriate priority whether originating from a wired IP phone or a wireless softclient, guaranteeing a high-quality user experience.

Scalable Wireless Management

The embedded controller can manage a specific number of access points (APs), making the WS-C3850-12X48U-L an ideal aggregation point for a floor or building.

Centralized Management

All configuration, radio resource management (RRM), and troubleshooting for connected APs are handled through the same IOS XE CLI or web interface used for the switch, creating a single pane of glass for network management.

Advanced Security and Visibility Features

In today's threat landscape, an access switch must be a first line of defense. The Catalyst 3850 is built with comprehensive, multi-layered security.

Threat Defense and Access Control

The switch provides robust tools to segment the network, control access, and mitigate attacks.

Cisco TrustSec Technology

This uses Software-Defined Access (SD-Access) principles to classify devices with security group tags (SGTs), enabling enforcement of policies based on identity rather than just IP address, which is dynamic and less secure.

Advanced ACLs and Storm Control

It supports extended and time-based access control lists (ACLs) for granular traffic filtering, along with broadcast, multicast, and unicast storm control to protect network bandwidth from malfunctioning or malicious devices.

Deep Network Analytics with Cisco DNA Advantage

When licensed with Cisco DNA Advantage, the switch unlocks powerful analytics and assurance capabilities.

Encrypted Traffic Analytics (ETA)

A groundbreaking feature that uses machine learning to detect threats in encrypted traffic without decrypting it, preserving privacy while enhancing security.

Application Visibility and Control (AVC)

Uses deep packet inspection (DPI) to recognize over 1400 applications, allowing IT to create policies that prioritize business-critical apps and limit non-essential traffic.

Deployment Scenarios and Ideal Use Cases

The Cisco WS-C3850-12X48U-L is versatile and suited for several key deployment models in enterprise and campus environments.

Enterprise Campus Access Layer

Its most common role is as a stackable access layer switch in office buildings, corporate campuses, and educational institutions.

High-Density Workspace Closets

Perfect for wiring closets serving multiple offices or classrooms, where its 48 PoE+ ports can connect numerous devices and its mGig ports future-proof the installation for high-speed wireless.

Branch Office Aggregation

In regional or large branch offices, a single stack can serve as the unified wired and wireless core, simplifying the branch network architecture and reducing the need for multiple devices.

Specialized Environments

Its robust feature set also makes it suitable for demanding vertical markets.

Healthcare

Supports a wide range of medical devices (IoMT), provides secure and prioritized networks for clinical systems, and powers wireless phones and tracking systems.

Retail and Hospitality

Powers point-of-sale systems, digital signage, surveillance cameras, and provides blanket guest and operations Wi-Fi, all with appropriate segmentation.

Software Licensing and Cisco DNA

Understanding the software licensing model is crucial. The switch comes with IP Base or IP Services feature sets, and can be enhanced with Cisco DNA subscriptions.

Cisco DNA Essentials and Advantage

These subscription tiers unlock the full potential of intent-based networking.

DNA Essentials

Provides foundational automation and basic assurance features, including zero-touch deployment, simplified device onboarding, and basic network analytics.

DNA Advantage

Includes all Essentials features plus the advanced security and analytics capabilities like ETA, AVC, and Software-Defined Access (SD-Access) for pervasive segmentation and policy enforcement.

Comparative Advantages and Strategic Value

Choosing the WS-C3850-12X48U-L over traditional disjointed access solutions offers tangible business benefits.

Total Cost of Ownership (TCO) Reduction

By eliminating separate wireless controllers and reducing the number of devices to manage, it lowers capital expenditures (CapEx) and operational expenditures (OpEx) through simplified management and reduced power and rack space requirements.

Future-Proof Investment

With support for Multigigabit Ethernet, programmability through IOS XE, and the capacity to run Cisco DNA services, this switch platform is designed to adapt to new technologies, protocols, and business requirements for years to come, protecting the network investment.

Operational Excellence

The convergence of management, coupled with features like StackWise and unified policies, dramatically reduces the complexity of network operations, minimizes human error, and accelerates the resolution of network issues, leading to higher overall network availability and IT staff productivity.