How the LibreRouter can power another device with POE Passthrough

The LibreRouter has the capacity of powering devices that you connect to it over ethernet cable with a feature called “PoE Passthrough”.

PoE passthrough works as folows when activated:

  • If the LibreRouter gets its power supply through the DC connector then both ethernet ports act as PoE power supplies.
  • If the LibreRouter gets its power supply through an Ethernet connector port then the other ethernet port acts as a PoE power supply.

The ethernet power supplies voltage are the same as the input. So if the device is powered from a 24V supply then the PoE passthrough is of 24V.

There are two ways of enabling the PoE passthrough depending on the LibreRouter board version:

  • The latest version have a switch near the power ports to activate the PoE passthrogh. It can also be activated through software config.
  • The old version can be activated only through software activation (see below software activation).

BE VERY CAREFUL when enabling this functionality, as it will make power run over the ethernet cable that you connect to it, and if the device that is on connected to the other side is not POE capable, you might end up burning its network adaptor.

Software activation

LibreRouterOs version 1.4 or newer

Add the following config in /etc/config/lime-node.

config generic_uci_config gpio_pass
	list uci_set 'system.poe_passthrough.value=1'

and then add the following line to /etc/rc.local:

devmem 0x1804006c 32 $(($(devmem 0x1804006c 32) | 0x2))

and finally run lime-config and reboot.

LibreROuterOs version 1.3 or older

To do so, connect to the device over SSH, and add the following lines to the file `/etc/rc.local:

echo "1"   > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio1/direction
echo "1"   > /sys/class/gpio/gpio1/value

and reboot.

1 Like

Thanks @nicopace!
Can’t we connect the second device to inner most ethernet socket?
I’m thinking of a setup where you have a LibreRouter connected to a gateway at the WAN (outter most) socket, and you want to connect a second LibreRouter to it.

From what I understand, you the inner most connector is the POE-in, and the outer-most connector is the POE-out, and shouldn’t be connected the other way.

For #developers, It would be possible from software to make the POE-in socket the WAN connector, or maybe in the future for the router to detect what the socket is and use it without user intervention.

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Gracias @nicopace!
Nos pasa que cada vez que el nodo se reinicia se apaga la antena que tiene conectada en el puerto wan.
Con ayuda de @SAn, coloqué esas líneas

echo "1"   > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio1/direction
echo "1"   > /sys/class/gpio/gpio1/value

en /etc/rc.local para que encienda el equipo conectado en cada reinicio.
Gracias!

Buenos Días!
Cómo están?
Encontramos que actualizando a las nuevas versiones 1.4.x los comandos anteriores no habilitan la alimentación del otro aparato en el puerto WAN
Me ayudarían a actualizar esta data para poder hacer poe passtrhrough con la versión LROs1.4.2 en un Librerouter V1 (sin switch passtrought on-off)…

Muchas Gracias!
Pablo.-

Hola Pablo! Actualicé la explicación del primer post de este hilo con el detalle de cómo hacerlo en las nuevas versiones y una explicación un poco mas en detalle de como funciona el PoE pass. Podes confirmar de que te funciona esta solución?

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Guau!
Combino con la red la actualización y les comento cómo salió :slight_smile:
Muchas Gracias!

La versión 1.4 (1.4.1 y 1.4.2) tienen un problema y la config que pasé no es suficiente para que ande el PoE passthrough por software. En breve agrego mas información de cómo hacerlo

Actualicé las instrucciones para las versiones 1.4, 1.4.1 y 1.4.2.

2 Likes

perfecto! Gracias @SAn. funcionó siguiendo las instrucciones. :wink::ok_hand:

1 Like