Check to see if POE (small black box with one or two colored lights – LAN/POE) has power. If not, check electrical connections, this is a common failure point for both residences and businesses. Check to see if you can reach your router internally. When a problem occurs with PoE, in most cases, the error symptom can be simply shown as the PoE switch not providing power, and the powered devices will stop. Power over Ethernet (PoE) simplifies device deployment by delivering both data and power over a single Ethernet cable. However, when PoE fails, it can disable critical infrastructure like IP phones, wireless access points, and security cameras. This is the second time this happened this quarter. Only a hardware switch restart seems to help (or at least was the mehod that worked for me). At 1:01 AM, the controller logged the unavailability of the. Looking into it further i found that while the port gave POE to any POE device it did not give any network connection to anything ever, ive done some research and couldn't find any reason for such a problem so what could have caused this to happen? as id like to prevent it happening again. To be. Power over Ethernet (PoE) is a convenient technology that enables network cables to carry electrical power, eliminating the need for additional wiring.