POE working but no LED and web GUI / CLI show 0 for consumption

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POE working but no LED and web GUI / CLI show 0 for consumption

This thread has been locked for further replies. You can start a new thread to share your ideas or ask questions.
POE working but no LED and web GUI / CLI show 0 for consumption
POE working but no LED and web GUI / CLI show 0 for consumption
2023-06-09 22:50:12
Tags: #PoE
Model: SG2210P  
Hardware Version: V5
Firmware Version: 5.0.5

Hi,

 

I have a TP-Link S2210P Rev 5.0 with 5.0.5 firmware (the same with 5.0.4).

 

On port 1 (tried port 2, same problem) POE is enabled and the cable is connected to Mikrotik CRS309 on port ETH which accepts POE power.

On CRS309 I have a second power supply (direct DC).

 

The TP-Link indicates that POE is inactive and power consumption is 0 (the same with GUI or CLI).

 

But... POE is clearly working !!

If I remove the second power supply on Mikrotik, it still works.

 

To be sure, I tried to remove the cable between TP-Link and Mikrotik and the Mikrotik switch turns off instantly.

 

So it might have a problem on SG2210P which is unable to see that POE is used on the port and is unable to measure the power consumption (on the port and global).

 

Is it possible to solve ?

 

Thanks

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#1
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6 Reply
Re:POE working but no LED and web GUI / CLI show 0 for consumption
2023-06-13 13:32:24

  @Cryptage 

 

You might be chasing ghosts...do you know if the Mikrotik prefers line power over POE?  If so, then it may really be drawing 0W when the wall power is active, and that's what the system would report.  It may take some time after the wall power is removed for the switch to start reporting the actual consumption.

 

If you power up the entire system, but with the Mikrotik ONLY powered via POE, does the 2210P POE port report correctly?  

<< Paying it forward, one juicy problem at a time... >>
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#2
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Re:POE working but no LED and web GUI / CLI show 0 for consumption
2023-06-14 18:42:33

  @d0ugmac1 

 

Thanks for helping.

 

Mikrotik prefers the source with higher voltage so it should take POE because line power is 24V.

I tried to wait a few minutes with POE only, to reboot Mikrotik, to reboot TP-Link... but that's always the same : no POE detected and 0W but clearly POE works because the Mikrotik stays up.

 

I tried another port, another RJ45 cable : no change.

 

So I clearly think it's a bug in firmware.

 

I've opened a support ticket and they told me they transferred the problem to R&D. We'll see...

 

 

 

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#3
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Re:POE working but no LED and web GUI / CLI show 0 for consumption
2023-07-12 12:22:42

Hi,

 

For information, the problem was the DAC cable on SFP port.

TP-Link support told me that SG2210P does not officially support DAC cable (it creates a closed loop) and that's why POE LED does not work.

 

I have to replace DAC with RJ45 copper SFP if I want to solve my problem.

 

Hope this helps.

 

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#4
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Re:POE working but no LED and web GUI / CLI show 0 for consumption
2023-07-12 21:58:56

I've made some tests with SFP Fiber modules (supported according to SG2210P datasheet) but it's not working better... It's even worse because there's no POE LED and POE is not working contrary to DAC cable.


So there's clearly a POE management problem on SG2210P model and I think TP-Link knows perfectly this problem but can't or don't want to solve it...


I asked to support for more information but I think I won't get anything else. It's really disappointing...

 

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#5
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Re:POE working but no LED and web GUI / CLI show 0 for consumption
2023-07-13 06:01:34

  @Cryptage 

1. what and why does it relate to DAC? fiber has nothing to do with the poe

2. do you ever suspect this could be a problem with the poe controller on the motherboard? Which may not support your meraki device due to its failover power supply design.

you blame the tplink switch not capable of showing correct power, but did you do a comparison test with a different switch to verify your presumption?

3. power failover is not common practice on tplink products and if there is one, that'll be dc power brick instead of poe as a backup power source. 

4. if you run a poe device like an access point, does it work and show power consumption correctly? if it does, it means the poe and its controller works and can recognize and assign the correct current and voltage. 

 

this explains that could be a power circuit design on meraki that is special causing the tplink poe controller fails to recognize the power needed and assign power. 

think of this in a different way. you need some other tests. 

ScReW yOu gUyS. I aM GOinG hoMe. —————————————————————— For heaven's sake, can you write and describe your issue based on plain fact, common logic and a methodologic approach? Appreciate it.
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#6
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Re:POE working but no LED and web GUI / CLI show 0 for consumption
2023-07-13 19:56:18 - last edited 2023-07-13 19:59:11

  @Tedd404 

 

1- The support told me that DAC cable are usually used with 10G but SFP cages are 1 Gbps only on SG2210P.

When DAC cable are used it creates a closed loop which prevents POE LED to light up.

 

I was really skeptical at first but when I reconnected DAC when POE LED was working it instantly turned off so they may be right...

 

I don't think the problem is with Mikrotik, even if I suspect it's capricious with some switches.

There's clearly something strange on SG2210P.

 

With POE + DC Power :

- With DAC cable : no POE LED but POE works.

- With Fiber SFP : no POE LED and POE does not work.

 

With POE only for booting then DC Power :

- With DAC cable : POE LED and POE work. If I reboot SG2210P POE works but not POE LED.

- With Fiber SFP : POE LED and POE work. If I reboot SG2210P POE does not work and POE LED neither.

 

I've opened a case with Mikrotik support. No answer for now.

 

2- I've tried with Linksys LGS310MPC and POE (and POE LED) works every time.

On Zyxel GS1900-10HP POE doesn't seem to work at all.

 

3- The dual power is supported on Mikrotik as failover mode.

The main source should be the one with the highest voltage, so POE (48V, 24V for DC adapter).

 

Unfortunately there's no command to check power state on Mikrotik.

 

4- Other POE devices work perfectly (1 access point, 2 cameras). Only Mikrotik switch has POE LED problem (whatever port you use).

As indicated, if I start switch with POE only, I have POE LED working but when I reboot switch, LED does not work anymore (POE does, except is fiber SFP is used).

 

 

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#7
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