In my lab I’ve got:
a 7.0.5 powered r5009,
a 6.48.6-powered hex PoE
a 6.48.6-powered RB2011
and an old DLink DGS-1210-10P switch in my lab.
When I plug an Ethernet patch cord between this DLink switch and the hex PoE, this later one powers up.
When I plug it into the r5009, it remains powered off.
When I plug this cable into RBPOE-CON-HP (48 to 24V PoE converter) 48V side and another cord from the 24V into the r5009, it powers up !
Is 24V PoE required ? Datasheet doesn’t mention this.
An other test, when I plug r5009-provided power supply (which is rated 24V/1.5A) in, my r5009 powers on.
Then if I plug a direct patch cord to the DLink switch, it still operates normally.
If I then unplug the power supply, it still runs OK.
So it seems r5009 requires 24V to power on and once started, it can run with 48V.
Can someone else reproduce this ?
As the only port accepting PoE-in in 2.5Gb/s, is there any PoE converter that accepts 2.5 Gb/s ?
The way PoE works is that there’s some more or less sophisticated handshake between PSE (power sourcing equipment, e.g. DGS-1210-10P) and PD (powered device, e.g. RB5009) before PSE enables power-out. (802.3 af/at specifies fairly sophisticated handshake while passive PoE uses a very plain one). While both RB5009 and DGS are supposed to be 802.3 af/at compliant, it seems that DGS is not happy about handshake with RB5009 and doesn’t enable power out if RB5009 is cold-booting. OTOH handshake seems to end successfully if RB5009 is already powered up before they are connected with ethernet cable.
What you can do: look at DGS management interface to see PoE-out status when RB5009 fails to boot, perhaps DGS will display something about it. Also observe total PoE power budget of DGS, it’s up to 65W (sum over all ports). RB5009 consumes up to 20W (or 14W without attachments) with boot-time power consumption likely very near this maximum and run-time power consumption at low usage likely a bit lower.
And file a problem ticket with support@mikrotik.com if you’re absolutely sure it’s not DGS’ doing … because RB5009 should be able to boot with any power source within specifications, it’s declared to be 802.3 af/at compatible.
I plugged my r5009 to an old DLink DES-1210-08P (Fast Ethernet only): no powering on.
I left it connected while working on other things during at least 15 minutes, and I saw it powered on !
Looking at DHCP logs, if necessary, I think I can have an exact measure of elapsed time between cord plug and r5009 asking for a dynamic address.
I’m certain my old DGS doesn’t support 802.3at but 802.3af only.
So if a r5009 requires 14W for booting, it’s quite possible a 802.3af source is unable to deliver this.
What seems quite strange is that converting the same 48V source to a 24V input somehow works around this PoE budget limit.
Seeing RB5009 boot after minutes of being connected to 802.3af source would indicate that hanshake between RB and (all of) DGS doesn’t always happen the way DGS are expecting. The fact that RB boots fine if connected via 48V-to-24V converter simply prooves that converter is fine with DGS … and that passive 24V PoE provided by converter is compatible with Mikrotik’s passive PoE.
I still think you should pay attention to DGS management UI while RB is set to boot to see what DGS has to say about it. Otherwise the whole troubleshooting exercise will look like whack-a-mole game.