Ensure power inline never is not set on the interface (show running-config interface ). Inspect and replace cables; verify cable length ≤ 100m. Confirm that automatic power management is enabled. However, when PoE fails, it can disable critical infrastructure like IP phones, wireless access points, and security cameras. This guide provides a step-by-step troubleshooting framework focusing on Cisco Catalyst switches (notably the 9300 and 2960 series), covering error categories, CLI commands. If your Cisco switch PoE is not working, the most common causes are an exhausted PoE power budget, a disabled inline power configuration, physical cable faults, incompatible powered devices (PD), or a crashed PoE controller. To isolate the problem fast, log into the Catalyst switch and run show. Obtain as much detail as possible regarding the symptom, including any system messages from the PoE switch. Did the trouble occur on initial installation, or did it begin after the powered device was working normally? If the trouble started after the powered device was working, what changed? Were. Despite its convenience, PoE can sometimes fail or behave unpredictably, causing devices to lose power, intermittently disconnect, or fail to start.
