strange ethernet related problem

caplam

Hello every one.

I'm a new user and begin with 2 orange pi zero (512Mb with a 2usb board).
I'm dealing with a strange problem.
I struggled a bit for having both my pi zero booting and working correctly. It's now done.
I wanted to put them at their definitive place; and it was impossible to communicate. The green and the yellow ethernet leds are blinking slowly.

The switch tells me the link is down on the port.
I did multiple tries, starting with checking my lan cables.
The conclusion is that both of my orange pi zero won't communicate when plugged in a port of my hp procurve  2810-48G switch.
When they are plugged in a apple airport extreme or in a dlink switch they operate normally (the airport and the dlink switch are both plugged in the hp switch)
In the hp switch manager the link appears to be down.
All my others devices (and i have a bunch) have no problem connecting on my switch.
Could you point me to a direction where to search as i don't see what i can do more?
I've never seen such an incompatibility. Seems to be a problem of electric level.

caplam

I was looking at the schematics and found a solution.
I simply change configuration of the hp switch port from auto to 100-Fdx.
Nevertheless i find stupid the wiring of ethernet port. If you support POE you have to do it fully and not half the way.
If you don't want support of poe, well people can always buy poe adapters. I doubt pepople will solder cms resistors to have poe.

What is strange here is that my hp switch is L2 switch i can change somme settings. By default all ports are left with auto config and visibly it can't negotiate the right speed with the pi zero. I have to set it up to 100 full duplex.
With my dlink switch i can't do it. The config of the ports is automatic and it works.