PoE with Cisco Wireless Access Points

[Jason Scott]

We have some Cisco 1130 access points that fail to power up properly when connected to HP powered switches. Can someone confirm please that the power implementation on HP does conform strictly to 802.3af standards? We are being told by Cisco that this problem is because the switch is not delivering enough power correctly.

Furthermore plugging the access point into a Powerdsine patch panel works, pointing the blame at the HP switch.

Thanks,

[SCOOTER]

Hi Jason,

All Procurve PoE switches do comply to the 3af standard.

What Procurve switch do you have?

Regards,

SCOOTER

[Jason Scott]

We've got a mix of 2650PWRs and 2626PWRs. The Cisco 1130 AP comes up with a warning that there is insufficient power to run the wireless chipsets.

We've not had this trouble with HP access points or Mitel IP telephones. We're evaluating between Cisco and Aruba for wireless and this is a sticking point for Cisco atm :)

[SCOOTER]

Jason,

Correct me If I'm wrong but the errors occur on the 2650 only and not on the 2626?

See FAQ:

http://www.hp.com/rnd/support/faqs/2600-pwr.htm

for the power distribution, it seems to be different for the 2626 and 2650. Question 4 5 and 6 are interesting for you to have a look at.

BTW The Cisco needs at least 15.4W of power on the port, with at least 12.95W delivered to the powered devices.

Regards,

SCOOTER

[Jason Scott]

Nope, sorry they're occuring on the 2626 too. I've debugged the port and it shows:

Priority: High
Detection Status: Delivering
Power Class: 3
Voltage: 498 dV
Power: 4473 mW
Current: 90 mA

Over Current Cnt: 0
Power denied Cnt: 0
MPS Absent Cnt: 0
Short Cnt: 0

Cisco are telling us that class 3 is wrong and that 4473mw is also incorrect.

[SCOOTER]

Hi Jason,

I have no idea what the values should be. Better contact HP Support? On the other hand if Cisco say the values are wrong did they say what the values should be?

Regards,

SCOOTER

[Jason Scott]

Cisco haven't given us an idea yet, although looking at the HP documentation I think they are wrong. Class 3 is the highest power that can be assigned to a device and therefore should be sufficient.

I wouldn't be surprised if Cisco's 'standards' were still not fully standard.

[SCOOTER]

Jason,

Quote:
"I wouldn't be surprised if Cisco's 'standards' were still not fully standard."

You read my mind.

SCOOTER

[Greg_271]

Hi Jason,
We are having the same problem - we have Cisco WCS system with 2-4400 controllers, HP 2626pwr switches and Cisco 1130 AP's. Did you Resolve your Problem? If your did could you get back with some info. thanks

[Jason Scott]

Nope, no resolution. Logged a TACS call with HP and never had any response. Cisco similarly never got back to us.

We're going Aruba now for wireless. Stick with a company that specialises.

[Ardon]

Hi Jason,

I can recall a case some time ago we worked on with similar symptoms and the following commands:

*Telnet to the Cisco AP
*In Enable Mode (#) issue the following command "Power inline negotiation injector xxxx.xxxx.xxxx (= MAC Address of the Switch Port which can be seen in the Web Interface).

Hope this helps.

Regards, Ardon

[Jason Scott]

Thanks Ardon, I'll make a note of that although as mentioned, we're moving away from Cisco now.

[Greg_271]

Thanks for the Rely. We figured out the problem. We had to turn the CDP global off the switches. This fixed the problem and the AP's are recieving the power needed now.