Cisco 2960PD actually getting power via PoE?

bmagedanz · ‎03-06-2010

Hi everyone,

I've got a C2960PD-8TT-L that is supposed to be able to take PoE over it's 10/100/1000 port (which also bears the label 'PoE Input'). I'm trying to power it from a C3524-PWR-XL and it is not working. I've tried about everything at this point. It works fine with a 48v brick plugged into the AC input on the back but I can't get it to come up with PoE. I've tried the 3524 switch (which powers an Aironet and a 7960 phone just fine) and an external PoE injector with no success. If it's powered from the wall, the 3524 is showing it as ILP-Device unknown.

Is there some trick I'm missing here?

Thanks in advance for any help.

-Byron

Leo Laohoo · ‎03-07-2010

Is CDP enabled on both switches?

bmagedanz · ‎03-07-2010

Yes, CDP is enabled and they both show up:

c2960#sho cdp nei

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone

Device ID Local Intrfce Holdtme Capability Platform Port ID

c3524 Gig 0/1 157 T S WS-C3524- Fas 0/14

_____

c3524#sho cdp nei

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater

Device ID Local Intrfce Holdtme Capability Platform Port ID

c2960 Fas 0/14 133 S I WS-C2960PDGig 0/1

kmccourt · ‎03-07-2010

I suspect you may have a mismatch between the older pre-standard PoE implementation of the C3524-PWR-XL and the 802.3af PoE standard supported on the C2960PD-8TT-L.

Was the PoE injector you tried out 802.3af compliant?

bmagedanz · ‎03-07-2010

Ok, that's interesting... Maybe not.

The power injector I tried was an old Aironet injector, AIR-PWRINJ3.There is no 802.3af compliance markings on it, so I'm guessing probably not.

If that's the case, is there a workaround?

Thanks again.

kmccourt · ‎03-07-2010

The AIR-PWRINJ3 is pretty old and I suspect it predates the standard. However I may have one in the office and if so I'll try it out on our C2960-PD-8TT-L later today to test if it works.

Also, according to http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps6406/prod_qas0900aecd80322c37.html, "the Cisco Catalyst 2960PD-8TT-L can be powered by another PoE switch, a power adaptor or power injectors that support 802.3af, including AIR-PWRINJ4."

I'm afraid I know of some solutions to get pre-802.3af equipment to work with 802.3af PoE power sources, but not the other way round. Maybe someone else can help on that one?