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MikroTik App
 
digit
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Posts: 22
Joined: Thu Apr 01, 2010 7:07 pm

GPeR

Fri Dec 03, 2021 12:14 am

two questions:

1)


Jumper usage
###########
If the destination device does not support PoE powering, the power passthrough can be disabled manually by removing both jumpers on the "PoE out" side.


What about jumper on "PoE in" side ? Can't find any information on those

2)

[...]

Powering
#######
The device require power to the Ethernet port:
• Ethernet port accepts passive PoE or 802.3af/at DC 24 - 57 V⎓

[...]

Jumper usage
###########
This will only work if "PoE in" is served by passive PoE source, as 802.3af/at switches will not be able to power the GPeR itself.


Pretty confusing... can be powered or not by 802.3af/at ?

Test:
802.3af switch -> GPeR jumper on -> non poe device (laptop) : does not work, no link on GPeR, no link on laptop
802.3af switch -> GPeR jumper off -> non poe device (laptop) : does not work, no link on GPeR, no link on laptop
802.3af switch -> GPeR jumper on -> poe device (Access point) : it is working

My understanding is that GPeR can not negociate with 802.3af/at switch or injector to ask the switch to send power, so it is not compatible with 802.3af/at and should not be advertised as such.

If by luck, device connected to the PoE-out side is 802.3af/at, that remote device will negotiate with the 802.3at/af compliant switch or injector. GPeR will be passive passthrough until the PoE switch or injector apply power. Then the GPeR will sink current on the 802.3af/at activated link and become an ethernet switch. I have some doubt on long line or with multiple GPeR in series if that 802.3af/at negotiation can even work.

Can someone from Mikrotik can confirm and comment ?
 
scratchfury
just joined
Posts: 1
Joined: Fri Jan 28, 2022 10:39 pm

Re: GPeR

Fri Jan 28, 2022 10:49 pm

It seems like it most like it should be labeled like this:

PoE in | 802.3af/at passthrough or Passive PoE (24 - 57 V)

I'm glad I only bought one of these before finding out this limitation.

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