You have put a camera or an access point on a port with PoE-out, and the device stays dark. No light, no link, nothing. On its own power supply the same device starts straight away.
This chapter is about power. If the device does get power but cannot be reached, go to A switch or AP cannot be reached. If an access point comes up but never reports to the controller, see An AP does not join CAPsMAN.
Never set poe-out=forced-on on a port with something on it that does not expect PoE. With auto-on the router first checks whether a PoE device is attached; with forced-on it puts voltage on the pins regardless.
The quick checks, in order
- Can this port do PoE-out at all?
/interface ethernet poe print. A good answer is one line per port withpoe-out: auto-on. If your port is not listed, this model has no PoE-out there and that is the end of it. - What is the port doing now?
/interface ethernet poe monitor ether2 once. A good answer ispoe-out-status: powered-on, with apoe-out-voltageand apoe-out-currentthat match the device. The other answers tell the whole story:waiting-for-load(nothing is recognised),current-too-low(the device draws too little to be detected),short-circuit(cable or plug),overloadorpower-budget-exceeded(more power asked than available),disabled(the port is off). - How much is going through in total?
/system health print. On the models that report it you see the input voltage and the total consumption. If the voltage sags when you plug the device in, the supply is too small. - Is the port enabled?
/interface print where name=ether2. A disabled port delivers no power, even withpoe-out=auto-onset. - Does the same cable carry data? Put a laptop on it for a moment. A link at all means the cable is not dead; a link at 100 Mbit means you are missing pairs, and that often explains the power too.
- Does the device work on a separate injector? That is the fastest way to separate the router from the device.
The usual causes, most common first
Passive 24 V versus 802.3af/at
This is the big one. Many MikroTik models deliver passive PoE: they put 24 V (or the input voltage) on fixed pins, without any negotiation. A device that expects 802.3af or 802.3at first looks for a counterpart that announces itself properly, does not find one, and therefore never starts. The other way round, a passive device gets nothing from an af injector. Check your model's datasheet for which kind of PoE-out its ports deliver and which kind your device asks for, and otherwise use a separate injector of the right type.
The power budget is used up
Four access points on one small device with a 24 V supply of a little over an amp does not work. The router itself needs power too, and the total is limited by the adapter as well as by the board. Add up what your devices draw and compare it with what the supply delivers, with margin.
Too little current to be detected
A small device that draws almost nothing at rest can stay below the detection threshold: current-too-low. On such ports forced-on is the intended answer, but only when you are certain what is attached.
The cable
PoE uses the pairs. A damaged pair, a poor connection or a long run with thin cores gives you voltage drop: the device starts, draws current, the voltage sags, the device restarts. An endless restart loop is almost always the cable or the distance.
The wrong port
PoE-in and PoE-out are not the same thing. The port that feeds the router itself does not pass power on.
What the configurator does about it
The Bridge and ports section has a list called PoE-out per port. It only appears for models the catalogue knows have PoE-out ports, and each row is a port plus a mode: auto-on, forced-on or off. The script writes one line per port from it: /interface ethernet set ether2 poe-out=auto-on.
That is all of it. There is no power budget anywhere in the tool. The configurator does not know how many watts your board or your adapter can deliver, does not know what your camera or access point draws, and therefore never warns that you have hung too much on it. It does not set poe-priority or poe-voltage either, and it does not know whether a port delivers passive 24 V or 802.3af/at. That sum is yours to do, from your model's datasheet.
The site checks do not look at PoE either. Draw a cable from a router to an access point on the network board and no PoE is switched on for that port and nothing is said about power. The cabling decides trunk ports, not power.
One thing can get in your way: Disable unused ports and the Disabled ports list, both in the same section. A port switched off that way delivers no power, even with a PoE line written for it.
When it is not your router
The adapter, the separate injector, the device itself and the cable in the wall. Test in that order: device on its own supply, then device on an injector with a short cable, then the installation.
Read on: PoE-out, Cabling and PoE in practice and A wired port does not reach its speed.