Dell N2048P - PoE On but no Link

Hello lk2819,

It could be it needs more power than the port will provide:

Aruba AP-575 data sheet

https://dell.to/3GgOaff

POWER

Maximum (worst-case) power consumption:

- POE powered (dual ports): 32.0W

N2000 series spec sheet

https://dell.to/3G6c2lm

N2024P: 24x RJ45 10/100/1000Mb PoE+ (up to 30.8W)

Give this a try:

If an AP is not receiving an IP address.  Try plugging a known good laptop into the same switch port .  Verify that it receives an IP address thru DHCP when requested.  If the laptop receives an IP address properly then you will need to look at factory resetting the AP.

Hi Charles,

Thanks for your reply. We connected all AP-575's using only one Ethernet port, so according to the datasheet you mentioned: The Maximum (worst-case) power consumption : POE powered (single port, full function): is 26.1W. That is less than the maximum PoE power the N2048P can provide (max. 30.8W). 

I can also confirm DHCP is working, as other APs on the same VLAN and same switch do get a correct IP-address. All APs are brand new out-of the box without config. Any other option I can try to troubleshoot this issue? How is it consuming power (according to Power-Inline Status) but not giving Link?  

Hello,

please using Putty, send use the log of:

show tech-support 

and send the result here under the service tag of the switch

https://dell.to/3Z8mfqj

Then please send service tag in PM to Charles or to me.

thanks

Hi Marco, I have run the show tech-support command and saved the output. However I can't seem to upload it to the URL you send, I get this banner at the top of the page: 

Is there any other way I can share the output with you? 

Hi Marco,

I just now successfully uploaded the file and send you the servicetag, please see your private messages. Awaiting your response, thanks in advance. 

Hello,

can you retry now? I see that it works

Hello lk2819,

I received the private message with the service tag. I will gather the log for review.

Can you let me know the results of my previous question when you have time?

Hello lk2819,

Could you also private message me the service tag? 

Marco may be off shift now and I cannot get to his private messages.

I also have a few follow up questions:

Are you saying you have installations of this same AP-575 that are working?

We need to confirm the switch port is working correctly.

Are you confirming you did try a laptop on the port and it was able to get an IP?

Have you tried the AP in another port?

Have you tried manually assigning an IP for the AP?

I did see this in the installation guide. Can you confirm you have the glands? : Failure to use the included Ethernet cable glands can lead to connectivity and POE issues.

Answers to your questions: 

Are you saying you have installations of this same AP-575 that are working? Yes, correct. 

Are you confirming you did try a laptop on the port and it was able to get an IP? Yes, I can confirm the port / VLAN is working just fine, I tried by connecting my laptop and got link / a IP-address.  

Have you tried the AP in another port? I have tried just now, same behavior on another port. No link, yet the AP is consuming power according to 'show power inline gigabitethernet 1/0/24'..

Have you tried manually assigning an IP for the AP? I can't manage the AP if it has no link / no connection with the Aruba Controllers, so this is not an option I think. If there is no link, the AP does not get a IP and thus cannot communicate with the controllers to retrieve config.

Thank you for the update. I will gather the log for review.

Have you contacted Aruba for support?

I ask that because another device can get an IP on the port and not the Access Point.

Are any of the AP-575s that are working connected to N2048P also?

Can you confirm you have the glands? : Failure to use the included Ethernet cable glands can lead to connectivity and POE issues.

I found this you may check if LLDP is supported on your Aruba OS

"In the Aruba OS 6.1, LLDP is not supported for Aruba AP's.

Starting from Aruba OS 6.2, LLDP support has been added for Aruba AP's."

ref: https://dell.to/3CrXdZp

We have seen that some PoE devices do not like the EEE optional LLDP med TLV and work fine if this feature is disabled on the port.

Try turning off green mode to test if the Arubas don't like the optional LLDP med TLV. It won't hurt anything.

The command is run on the switch, every interface on the switch that is using POE.

console#conf

console (config) #interface gi1/0/1

console (config-if-Gi1/0/1) #no green-mode eee

Hi Marco, thanks again, I hope this answers your questions: 

Have you contacted Aruba for support? > No I have not yet, I will contact them as well. 

Failure to use the included Ethernet cable glands can lead to connectivity and POE issues. > I understand this, but due to the patching infrastructure, we are not able to use the included Ethernet cables. We have several APs (also a few AP-575's) up and running just fine by using our own cables. I understand your question but can't imagine that this is the source of the problem.   

Are any of the AP-575s that are working connected to N2048P also? > Yes, I have two AP-575's connected to another N2048P switch running firmware version 6.6.3.10 (older firmware than the switches described here). Those are working just fine: 

I found this you may check if LLDP is supported on your Aruba OS > We are running ArubaOS 8.7.x.x, so this should no be an issue. Other working APs connected to the same controller. 

We have seen that some PoE devices do not like the EEE optional LLDP med TLV and work fine if this feature is disabled on the port. > I just now tried by running 'no green-mode eee' on that port, no changes to Link status. 

Hello lk2819,

Thank you for the response to the questions.

Let us know what Aruba says. Also please check with them about the gland as their documentation states failure to use it can lead to connectivity and POE issues.

Do you have the ability to try this AP on the switch that does have one connecting normally, or try the working AP connect to this switch,  to see if the issue follows this AP?

We know the port can link and assign IP to a laptop. Do you happen to have another POE device such as a VoIP phone you can try in the port?

Hi Charles,

Do you have the ability to try this AP on the switch that does have one connecting normally, or try the working AP connect to this switch,to see if the issue follows this AP? > Since the AP-575 described in this case is already mounted to a wall, I do not have the ability to pickup this AP and physically move it to the working switch. I do have another AP-575, which I can test on both the 'working' switch and the switches described in this case as 'not working'. I will try this out. 

We know the port can link and assign IP to a laptop. Do you happen to have another POE device such as a VoIP phone you can try in the port? > Yes, I can confirm there are multiple working devices that use PoE on those switches (VoIP Phones, other APs, etc.).

Let me know if you have any update on the investigation of this issue, in the meanwhile I am waiting on response from Aruba's Support.