How do I enable Power over Ethernet?

[jaybird43]

Hi everyone

I recently called VirginMedia technical support as I was about to purchase a PoE (Power over Ethernet) adapter for my raspberry pi, and I wanted to check if my Hub 3 supported that protocol (I suspected not). I was told that the Hub 5 supported it (I asked them to double check the specifications i.e. IEEE 802.3af) and that they would send me a new hub.

So I went ahead and purchased the adapter, received the new hub5 and have just gone through setting up my home network again along with the various mesh network points.

My problem is that I have now plugged in the PoE adapter into an ethernet port, and the USB cable from that adapter into the raspberry pi and it's not receiving any power (it is fine from a standard PSU).

I'm now worried that the call centre person was not sure what they were confirming when I asked them to confirm that the hub supported IEEE 802.3af (power over ethernet, not to be confused with ethernet over power which is what many people use for their "homeplug" systems).

Anyone know if this is something I need to enable? Or if the hub5 supports it at all?

Many thanks

J

[jbrennand]

I dont believe so -  but I know that @Tudor  uses POE and pi's - so he may comment soon.

[legacy1]

Its got nothing to do with the hub it will not give out power and never will.

May be your PoE adapter is dead? or bad cable

The Power over Ethernet adapter Injector will have one port for Data and one for Power + Data don't get them the wrong way round over a cable with 4 pairs.

Their are many power types of PoE 15.4 W, 30W,60W not sure how much power a raspberry pi will need.

Found this

Using PoE With A Raspberry Pi 3 For About Two Bucks | Hackaday

[jaybird43]

This is the adapter/splitter in question: https://thepihut.com/products/poe-splitter-with-microusb-plug-isolated-12w-5v-2-4-amp?variant=123640...

[jaybird43]

> Its got nothing to do with the hub it will not give out power and never will.

I must have completely misunderstood the requirements then. Based on the info I read on the pihut, I assumed that by checking with VirginMedia tech team that POE was supported on the hub, then that would be enough to get this to work (especially as they confirmed that yes the hub would support POE)

[carl_pearce]

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@jaybird43 wrote:

> Its got nothing to do with the hub it will not give out power and never will.

I must have completely misunderstood the requirements then. Based on the info I read on the pihut, I assumed that by checking with VirginMedia tech team that POE was supported on the hub, then that would be enough to get this to work (especially as they confirmed that yes the hub would support POE)

---

The HUBs do not provide POE.

[legacy1]

from what I can tell you need

ZHANGQING Gigabit PoE Injector 1 Port | GPOE-1-WM(No Power Included) Ethernet Injector IEEE 802.3af ...

+

12V 3A Power Adapter, 5.5ft AC to DC Power Supply Adapter 5.5 x 2.1mm Jack for Led Strips, CCTV Came...

Nope was right the first time the PoE Splitter you have needs power Input: 44~57V DC

PTZlink 60W POE Injector 48V Gigabit 10/100/1000Mbps Shielded RJ45 Passive Ultra POE+ Power Adapter ...

[jaybird43]

Thanks all for your fast responses, this is really helpful.

[Tudor · Accepted solution]

PoE should work with a Pi, depends on the model and how much power it requires. There are official HATs for a Pi 3 or 4 I use one successfully and ones on Amazon. What you MUST understand all of these a fed from a PoE network switch or an injector. The diagram is a little misleading, but essentially what you need is two components, an injector and an extractor, the items mentioned above are the extractors.

Basically an injector will only feed one item and a switch many like 4,8,16,24 or 48 PoE devices. The VM hub does not come into it at all as it is an upstream device 

[jem101]

Bottom line, I really hope you weren’t charged any sort of upgrade fee for the Hub 5 as that would constitute blatant misselling. None of the VM hubs have ever supplied PoE and the 5 is no exception, what you have run up against is the reality that the VM call centre staff are in absolutely no way ‘technical’, their skills consist of reading a predetermined script from a screen and blindly following the answers. Where a question or request doesn’t match the presented questions and answers, then they do have, ‘form’ shall we say, for simply making up answers and telling the unsuspecting mug valued customer, just what they want to hear, just to get you off the line and chalk up another successfully closed call. Now if said response also gets you for fork out for an upgrade or even a ‘soft upgrade’ (you might want to check that you haven’t been enrolled into a new minimum 18 month contract), then so much the better - trebles all round at VM Towers!

Now what you wanted to do is to avoid having a separate USB power supply for the Pi, yes? Well the Hub as it stands can’t support that, so you’ll need to either get a PoE capable switch (£100 or so) or a PoE injector (£20-30), honestly, just give it up and go back to having a separate power supply for the Pi.

John