Cisco Catalyst C9800-40-K9 Wireless LAN Controller
The Cisco Catalyst C9800-40-K9 is a high-performance, enterprise-class Wireless LAN Controller designed for large campuses. Delivering 40 Gbps of throughput and 4x 10G SFP+ uplinks, it seamlessly manages up to 2000 Access Points and 32,000 clients.
Quick Specs:
· Capacity: 2,000 Access Points (APs) / 32,000 Clients
· Throughput: 40 Gbps
· Uplinks: 4 x 1G/10G SFP+ (Fiber)
· Operating System: Cisco IOS XE
· High Availability: Dual Redundant Power & Modular Fans
· Form Factor: 1RU Rack-mountable (Full-width)
Comprehensive Product Overview
The Cisco Catalyst C9800-40-K9 represents the pinnacle of intent-based wireless networking. As a flagship Wireless LAN Controller (WLC) running on the highly programmable Cisco IOS XE operating system, it is engineered to meet the extreme demands of large enterprise campuses, universities, and healthcare facilities rapidly transitioning to Wi-Fi 6 (802.11ax) and Wi-Fi 6E technologies. Designed for uncompromising scalability and resilience, the C9800-40 bridges the gap between massive wireless traffic and wired core networks. It delivers a staggering 40 Gbps of non-blocking wireless throughput. Unlike entry-level models, this full-width 1RU appliance features true enterprise-grade high availability, including dual redundant hot-swappable power supplies and modular cooling fans, ensuring your mission-critical wireless infrastructure remains active 24/7.
Key Features & Business Benefits
Massive Enterprise Scalability: Built to handle the densest wireless environments. A single C9800-40 controller can flawlessly manage up to 2,000 Access Points and support 32,000 simultaneous wireless clients, making it ideal for stadiums, large hospitals, and massive corporate headquarters.
Ultra-High 40 Gbps Throughput: Equipped with four 1G/10G SFP+ optical uplink ports, the controller aggregates wireless traffic and routes it directly to your core network at speeds up to 40 Gigabits per second, completely eliminating wireless-to-wired bottlenecks.
Zero-Downtime High Availability: Features Stateful Switchover (SSO) allowing two controllers to operate in an Active/Standby cluster. Combined with hitless software upgrades, hot patching, and redundant hardware components (power/fans), it guarantees 99.999% uptime.
Advanced Threat Defense: Protect your wireless edge natively. The controller supports WPA3 encryption, MACsec, Cisco TrustSec for identity-based micro-segmentation, and Encrypted Traffic Analytics (ETA) to identify malware hidden in encrypted wireless data streams.
Cisco DNA Center Automation: Fully integrated into Cisco’s Software-Defined Access (SD-Access) architecture. Provision, manage, and troubleshoot your entire wired and wireless network from a single, centralized pane of glass using Cisco DNA Center.
Technical Specifications
Specification
Details for C9800-L-F-K9
Product Series
Cisco Catalyst 9800 Series
Maximum Access Points (APs)
250
Maximum Wireless Clients
5,000
Wireless Throughput
5 Gbps
Network Interfaces
4 x 1G/10G SFP+ (Fiber Optics)
Additional Ports
2 x 1G/2.5G RJ45 (for out-of-band management/redundancy)
Operating System
Cisco IOS XE Software
Maximum WLANs
4096
VLANs Supported
4096
High Availability
Stateful Switchover (SSO) Supported
Power Supply
Single internal 110W AC Power Supply
Dimensions (H x W x D)
1.73 x 8.5 x 9.06 in. (4.39 x 21.59 x 23.01 cm)
Ideal Application Scenarios
Large Enterprise Campus Core: The ultimate controller for multinational corporate headquarters needing to unify and secure wireless coverage across multiple large buildings and thousands of employee BYOD devices.
Higher Education & Universities: Easily handles the massive throughput and high client density required during peak class hours, supporting 32,000 student laptops, smartphones, and campus IoT devices effortlessly.
Hospitals & Healthcare Facilities: The dual redundant hardware and SSO capabilities ensure that mission-critical mobile medical carts, pagers, and patient monitoring systems never experience wireless downtime.
Supported Accessories, Optics & Licensing
Maximize the reliability and performance of your C9800-40-K9 by utilizing genuine Cisco components: SFP-10G-SR / SFP-10G-LR: 10GBASE-SR (Multi-mode) or LR (Single-mode) optical transceivers for uplink connectivity. PWR-C1-400WAC=: 400W AC Power Supply (Order two for N+1 redundancy). FAN-T1=: Cisco Catalyst 9800-40 redundant fan tray. Cisco DNA Software Subscriptions: Hardware licensing is not required for the controller itself. Instead, you must purchase a Cisco DNA Essentials or DNA Advantage subscription (3, 5, or 7 years) for each Access Point joining the network. Compatible Access Points: Natively supports Cisco Catalyst 9100 Series (Wi-Fi 6/6E) and Cisco Aironet 802.11ac Wave 1 / Wave 2 Access Points.
Frequently Asked Questions (FAQ)
Q1: What is the primary difference between the C9800-40 and the C9800-80?
A1: The numbers indicate the throughput capacity. The C9800-40 supports 40 Gbps of throughput and 2,000 APs. The massive C9800-80 supports up to 80 Gbps of throughput and up to 6,000 APs, making it suitable for service providers and the largest global enterprises.
Q2: Are the power supplies and fans hot-swappable?
A2: Yes. Unlike the smaller C9800-L series, the C9800-40-K9 features dual redundant power supply bays and modular fan trays. You can replace a failed power supply or fan unit while the controller is actively routing traffic, ensuring zero network downtime.
Q3: Do the four 10G SFP+ ports support link aggregation?
A3: Yes. You can configure the four 10G SFP+ ports using Link Aggregation Control Protocol (LACP) to create a single 40 Gbps logical port-channel to your core switches (such as a Catalyst 9500 or Nexus 9000).
Q4: Can I use this controller to manage older Cisco Aironet APs?
A4: Yes. The Catalyst 9800 series running Cisco IOS XE provides excellent backwards compatibility. It can manage modern Wi-Fi 6 Catalyst 9100 APs alongside older 802.11ac Wave 1 and Wave 2 Aironet APs (e.g., 2800, 3800 series) simultaneously.
Q5: Does the C9800-40 support Cisco SD-Access?
A5: Absolutely. The C9800-40-K9 is a foundational component of Cisco’s intent-based networking architecture. It fully integrates with Cisco DNA Center to act as the wireless control plane in an SD-Access fabric.
