WS-C3850-24P-E Cisco L3 24 Ports Ethernet Switch PoE+

Hardware Architecture & Performance Specifications

Built on Cisco's UADP ASIC (Application-Specific Integrated Circuit), the Catalyst 3850-24P-E delivers wire-rate Layer 2 and Layer 3 switching performance, ensuring no network bottlenecks even under full load across all ports.

Port Configuration & Power over Ethernet (PoE+) Capabilities

The front panel of the WS-C3850-24P-E hosts 24 autosensing 10/100/1000BASE-T Ethernet ports. Each port supports IEEE 802.3at PoE+ standard, providing up to 30 watts of power per port. This is a critical feature for powering a wide array of devices directly from the switch, eliminating the need for separate power injectors and AC outlets at the device location.

PoE Budget and Device Support

The switch features a substantial power supply with a total PoE budget of 440 watts. This allows administrators to power a mixed environment of high-demand devices such as:

802.11ac Wave 2 and Wi-Fi 6/6E Wireless Access PointsIP Phones and Video Phones
High-resolution PTZ (Pan-Tilt-Zoom) IP Security Cameras
Point-of-Sale (POS) terminals and digital signage
Thin clients and desktop computers

Intelligent power management features like Cisco's Universal Power Over Ethernet (UPOE) readiness and per-port power policing ensure optimal and reliable power delivery.

StackWise-480 Technology: Simplified Scalability

A cornerstone of the Catalyst 3850 series is Cisco's StackWise-480 technology. This allows up to nine individual Catalyst 3850 switches to be logically combined into a single, unified switching entity.

Benefits of a Stacked Configuration

Single Management Plane

The entire stack is managed as one device through one IP address, drastically reducing configuration and management overhead.

Increased Resiliency

The stack uses ring or chain topologies. If one switch fails, the stack automatically reorganizes, maintaining network availability. Stateful switchover (SSO) ensures sub-second convergence.

Unified Data & Control Planes

The stack creates a unified 480 Gbps backplane for inter-switch communication, enabling high-performance east-west traffic and simplified Layer 2/Layer 3 design.

Converged Access & Embedded Wireless Controller

The "Converged Access" model is what truly differentiates the Catalyst 3850 series. By embedding a full Wireless LAN Controller (WLC) into the switching hardware, Cisco unifies the management and policy enforcement for both wired and wireless clients.

Key Advantages of the Embedded WLC

This integration eliminates the need for a separate physical or virtual wireless controller appliance for small to medium deployments, reducing cost and complexity.

Unified Policy & Security

Access policies, Quality of Service (QoS) settings, and security features (like ACLs and Cisco TrustSec) are defined once and applied consistently, regardless of how a user connects—via Ethernet or Wi-Fi.

Seamless Mobility

Client devices can roam between wired ports and wireless access points, or between different APs, with minimal disruption. The switch handles client state information internally, enabling fast, secure roaming.

Scalable Wireless Support

The Catalyst 3850-24P-E with the IP Base (E) license supports the management and control of up to 50 Cisco Aironet access points and up to 2,000 wireless clients, making it an ideal solution for centralized wireless management in a campus or large branch.

Layer 3 Routing & Advanced Software Capabilities

Equipped with the IP Base software image, the WS-C3850-24P-E provides a rich set of routing protocols and enterprise features beyond simple switching.

IP Base Feature Set Breakdown

This license tier unlocks essential routing functionality for most enterprise access and distribution layer deployments.

Dynamic Routing Protocols

The switch supports static routing, RIPv1/v2, and EIGRP stub routing. This allows the switch to serve as a default gateway for its VLANs and participate in routing with core layer switches or routers, enabling efficient inter-VLAN routing and network segmentation.

Advanced Switching Features

Comprehensive feature support includes:

Spanning Tree Protocol: PVST+, Rapid PVST+, and MSTP for robust Layer 2 loop prevention and path redundancy.
Quality of Service (QoS): Advanced classification, marking, policing, and shaping based on Layer 2, 3, and 4 parameters to prioritize voice, video, and critical data traffic.
Multicast Routing: Protocol Independent Multicast (PIM) Sparse Mode for efficient delivery of video streams and multicast applications.
High Availability: Features like Hot Standby Router Protocol (HSRP) and Virtual Router Redundancy Protocol (VRRP) provide first-hop redundancy for default gateways.

Management & Programmability

The Catalyst 3850 offers multiple avenues for management and automation, aligning with modern network operations.

Traditional & Modern Interfaces

Administrators can manage the switch via the familiar Cisco IOS CLI (Command Line Interface), a web-based GUI (Device Manager), or through Cisco Prime Infrastructure for centralized management of larger deployments.

Programmability with APIs

The switch supports RESTful APIs and Python scripting, enabling network automation, configuration templating, and integration with IT orchestration tools—a step toward Software-Defined Access (SD-Access) readiness.

Comprehensive Security & Threat Mitigation

Enterprise networks require defense-in-depth. The Catalyst 3850-24P-E incorporates multiple layers of security to protect the network infrastructure and the data traversing it.

Network Access Control & Identity

Strong access control mechanisms ensure only authorized users and devices can connect.

IEEE 802.1X Authentication

Port-based NAC using standards-based 802.1X, with support for multiple supplicants and flexible authentication databases (RADIUS, TACACS+).

Cisco TrustSec

This technology tag packets with a Security Group Tag (SGT) at the ingress point (wired port or wireless connection). Policies (SGACLs) are then enforced anywhere in the network based on this tag, not just IP address, simplifying macro-segmentation.

Infrastructure Protection

The switch itself is hardened against attacks.

Control Plane Policing (CoPP)

Protects the switch's CPU from denial-of-service attacks by rate-limiting traffic destined to the management plane.

DHCP Snooping, IP Source Guard, Dynamic ARP Inspection

These features work in tandem to prevent common Layer 2 attacks like ARP spoofing, IP address spoofing, and rogue DHCP servers.

Switch Resiliency with STP Security

Features like BPDU Guard, Root Guard, and Loop Guard protect the integrity of the Spanning Tree topology.

Primary Deployment Scenarios & Use Cases

The versatile nature of the Cisco Catalyst WS-C3850-24P-E makes it suitable for several key roles in a hierarchical network design.

Enterprise Campus Access Layer

Its most common role is as a wired and wireless access switch in office buildings, connecting end-user devices, IP phones, and providing PoE+ to nearby wireless access points.

Branch Office / Medium Business Core

For smaller sites, a stacked pair of Catalyst 3850 switches can serve as the combined access, distribution, and core layer, providing full Layer 3 inter-VLAN routing, wireless management, and WAN edge connectivity in a compact, manageable form factor.

High-Density PoE Deployments

With its 440W PoE budget, the switch excels in environments dense with powered devices, such as modern classrooms, hospitals with wireless medical devices, and retail stores with numerous POS terminals, security cameras, and digital signs.