AireOS ran enterprise wireless for 15 years. The Cisco Catalyst 9800 rebuilds the controller on IOS-XE with a modular architecture and a new configuration model. A side-by-side look at what actually changed and why it matters.
The Cisco C9800 configuration model uses tags, profiles, and policies instead of flat global settings. A clear guide to the five core profiles and how they fit together to drive every AP and WLAN on the controller.
The Cisco Catalyst 9800 is a multiprocess, data-model-driven WLC built on IOS-XE. A deep dive into the hardware and software architecture including processes, dataplane, and fault domains for troubleshooting intelligence.
The Cisco Catalyst 9800 replaces AireOS-based WLCs with a modular IOS-XE platform. A platform overview covering every model, from C9800-L to C9800-CL and embedded, so you can pick the right controller for your deployment.
The Cisco Catalyst 9800 is the current generation of enterprise wireless controllers, built on IOS-XE and designed for Wi-Fi 6, 6E, and 7. A complete reference guide covering models, architecture, config model, and every core feature.
A good VLAN design scales cleanly, keeps STP domains small, and makes troubleshooting obvious. Here is how to plan VLANs for a multi-building campus network.
VLANs provide segmentation, not security. Without explicit hardening — disabling DTP, fixing the native VLAN, enabling DHCP snooping and DAI — your Layer 2 network is wide open to attack.
Inter-VLAN routing failures are usually caused by SVIs in down state, missing routes, DHCP misconfiguration, or ARP timeouts. Learn to diagnose and fix them systematically.
Most VLAN outages stem from ports in the wrong VLAN, trunks not allowing required VLAN, or native VLAN mismatches. Here's how to diagnose and fix them systematically.
Private VLANs let you enforce micro-segmentation within a single VLAN—isolating hosts completely or grouping them into communities while keeping them behind a single gateway IP.
Voice VLANs let a single access port carry both data traffic from a PC and voice traffic from an IP phone — each in its own VLAN with its own QoS treatment.
Layer 3 switches route between VLANs in hardware at wire speed — no external router bottleneck. Here is how to configure SVI-based inter-VLAN routing on a Catalyst 9300.