AIR-WLC2125-K9 Cisco 2100 Series Wireless Controller 25-AP

25 AP capacity on a Fast Ethernet controller

AIR-WLC2125-K9 is the Cisco 2100 Series hardware controller for up to 25 Cisco Aironet access points. Its chassis has eight 10/100 Mbps RJ-45 Ethernet ports, including two 802.3af PoE ports for supported Cisco lightweight APs. These are Fast Ethernet interfaces, not Gigabit uplinks; the 25-AP capacity is not a throughput or client-count specification.

Check the installed AP estate against the old controller

The 2125 capacity line differs from the six-AP AIR-WLC2106-K9 and twelve-AP AIR-WLC2112-K9. Before retaining this controller, compare the installed AP models and controller software with the required WLAN configuration. More licensed AP positions do not establish support for a later AP generation or remove the wired-interface limit.

A working unit can still have a power-cycle risk

Cisco FN63770 explicitly includes AIR-WLC2125-K9. The notice describes affected memory components that may expose a hard boot failure after an upgrade, reboot or power cycle; another reboot does not recover that failure. For a legacy replacement, preserve configuration and console access and prepare a replacement path before interrupting an operating unit. The notice does not mean every controller will fail.

Manufacturer support ended in 2017

Cisco marks the 2100 Series retired, with end of sale on May 2, 2012 and end of support on May 31, 2017. Evaluate this model as legacy hardware for an existing environment, not as a currently supported controller. For a new deployment, compare the AP estate, software architecture, power and migration requirements against a supported alternative. An archived field notice is not a promise of present-day RMA eligibility.

Cisco 2100 hardware and exact capacity ordering table | Cisco FN63770 affected models and boot failure | Cisco 2100 retirement and support dates