PoE status - HP vs. Juniper

[eglinsky2012]

We have a 5508 WLC running 8.2.151.0 code, and a mix of 3500, 3600, and 3700 APs. Our switches are Juniper EX3300 and EX4200 that do have PoE enabled up to 30W. In the WLC, the PoE status for all the APs connected to the Juniper switches is "Power injector / Normal mode". However, when connected to an HP/Aruba 2920 switch (which is also PoE+), the PoE status is "PoE/Full Power". This applies to a 3502i and a 3702e.

I'm wondering why the difference, and should I be concerned about the APs running to their potential (or not) either way?

Thanks for your insight ahead of time!

[Leo Laohoo]

There is an auto-regulator in the AP.  The AP might be fed full power but the AP will only draw the amount it needs to draw.

[eglinsky2012]

Leo: I don't understand how the manufacturer of the switch has an affect on how much power the AP draws.

[pwwiddicombe]

Do the switches have any reporting on the capabilities and status of PoE on devices?  3702 wants 18 watts instead of 15.4, but does negotiate with the switch.  If the switch doesn't understand the PoE class 4 or whatever, you will get "standard" power levels and the 3702 shuts down some of the antennas.

[eglinsky2012]

I don't have any 2800 APs connected to the Juniper switches right now, but in checking the PoE status currently, there are a bunch of class 4 (30W) devices connected (must be the 3700 APs; I also see 7W class 2 devices -- the IP phones, as well as a couple 15.4W class 3 devices -- probably 3500 APs).

So it seems like the APs are being provided all the power they need, I'm just confused why the Juniper switch makes the APs think they're connected via power injector, while the HP switch makes the APs (correctly) think they're on PoE with full power.

Leo, sorry for my previous response; I should have told you that every single AP connected to a Juniper switch reports that it's on power injector, whereas all the APs on the HP switch report that they're on PoE full power. So, perhaps we can rule out the AP not needing to draw max power. Although, come to think of it, I may have seen an AP report power injector status while booting on the HP switch; but after booting, it reported PoE full power.

[johnd2310]

Hi,

Do you have lldp-med configured on all the switches?

Thanks

John

[pwwiddicombe]

3702's should only take 18 w or so, unless you have the P or E version of those...  some of the more exotic outdoor AP's have little heaters in them for colder weather.

If it's a Cisco device, the sh power inline will usually identify the device type.  Possibly you have PoE cameras consuming 30 W ?

[marce1000]

 - Check the AP-log when it boot's  ; watch out for power issues, if any

M.