Passive POE with Raspberry Pi4

[LaurentLuyckx]

Hi All,

For one of my project, I'm testing a SMB-250 POE 16-ports with a raspberry pi4

So far, I wasn't able to power it up. However it's working fine on my Aruba 2530 (8 POE ports) if I activate the "Poe pre-standard" parameter.

I can't find such parameter on the CBS-250.

My questions are:

- Does the SMB-250 can make POE passive devices work?

- If yes, what should I do to make it power?

Thanks for all your help.

PS: I don't want to use a Poe injector instread. It should work from the switch.

[Georg Pauwen]

Hello,

tough one. There are a few things/settings you can play with, such as the Power Negotiation Protocol. I don't know which one the Raspberry uses...

https://www.cisco.com/c/en/us/td/docs/switches/lan/csbms/CBS_250_350/Administration-Guide/cbs-250-ag/port-management.html#ID-0000294d

[balaji.bandi]

When I was tested some time back with 3750 old one - RasPi Zero for the console - it was required - 802.3af  ( CBS do support AT and AF).

Since I am not on hand on the device - just look at the settings -

https://www.cisco.com/c/en/us/support/docs/smb/switches/cisco-small-business-200-series-smart-switches/smb1791-configuration-of-power-over-ethernet-poe-settings-on-cisco-2.html

[LaurentLuyckx]

Thank you for you replies.

I've already played with all those setting and couldn't made it power.

I'm wondering what Aruba does to have it powered on their switches.

[balaji.bandi]

what Pi you have (Raspberry Pi PoE HAT)

[LaurentLuyckx]

It's a pi4 with a custom board connected on the GPIO. The company who designed it told me that it's a passive POE. Actually the pi can be powered with an injector and the Aruba I own.