PoE+ issues with Aruba/HPE switches and PD's
PoE+ / 802.3at / Power over Ethernet Type2
This issue apparently applies to more devices and brands using PoE+ but since Extreme Networks is bringing out some new equipment lately, using new specifications, this information may or may not be useful for its readers. 🙂
I probably won’t be the first with this issue, but it did surprise me that I, apart from one single cached, page couldn’t find anything about this specific issue. Maybe I haven’t looked well enough on the internet?
Anyhow, my workplace switched over to the Extreme Networks AP305C since Aerohive’s (Now in possession of Extreme Network) AP130 is end-of-sale since July of 2020.
Not long ago we finally received our first batch of AP305C’s and I wanted to try them out in our office room. Onboarding and updating all went fine.
The problem I had and troubleshooting the problem
I noticed some odd blinking of the white LED. The AP was online in the ExtremeCloud IQ after all…
I found out of Extreme Cloud’s knowledge base that this means that the AP in question does receive PoE (802.3af) but is supposed to receive PoE+ (802.3at) instead. I knew the switches were up to the task, them being 2530’s (J9772A, J9774A and J9778A)
I emailed our reseller to let them know that we had an issue regarding those AP’s, I promised them to keep them updated too whenever I find the cause and/or solution.
The first I checked was the power-over-ethernet budget on the switch I had this AP305C hooked on to, along with other AP130 in production. I confirmed the PoE budget was not on it’s max, by far even below 50%, so I checked the LLDP statistics and it showed that the PD (Powered Device) was ‘type2’ indicating it is recognised as PoE+ (802.3at). Better said, it’s class was 4 which is only available for PoE+ devices.
Then checked the fact that the access point even did see the switch and its capabilities with LLDP, which it did too! I was quite at a loss. I have tried downgrades and upgrades of firmware both on the switch and the AP, without success. Then, I decided to take the AP home with me to try it on my Ubiquiti Unifi Switch 16-150W to my surprise, it did work! It must be the switch then by now.
The next day I tried it on other model switches, including the 2930F. Alas, same negative result. I ran a port mirror on the switch and used Wireshark but couldn’t really find anything useful at first until I sad it sended some non-MED LLDP frames to the AP. Which then freaked ou
The solution... For now.
After looking at the commands and HPE’s techhub regarding these commands I found out that the following command is able to help remove those faulty LLDP frames from messing up the LLDP negotiation:
no lldp config <interface(s)> dot3TlvEnable poeplus_config
Applying this command, thus disabling ‘dot3Tlv’ does destroy the whole PoE negotiation with LLDP. Luckily this is on a port per port basis. Below here are both the before and after terminal outputs of ‘show lldp info local-device / remote-device’:
I hope I can help out some people with this issue here since it was quite a challenge to look for the solution since it’s not hitting that many keyphrases on search engines, and the fact searching ‘Aruba’ along with ‘305’ doesn’t help either since Aruba also has an AP305. But as this problem applies to basically any device using PoE+ with an Aruba switch, this is a bit easier to find. But still so vague.
The next day I contacted our reseller after finding the solution. For at least what it is now. I did see that this is a years long thing, so I will try and search more stuff about it.
Please contact me on my email at the main page if you have any questions or commentaries.
More external sources
After finding the solution, I was able to do a reverse search on this on Google, seems there are more people around but most of the results are quite hard to find and some are not available directly on the forums of Extreme Network’s community. Though, Google luckily indexes it:
User having problems with AP305C. Solution rather being an solution for the symptom, not the cause. (Cached by google.)
Reddit post about PoE+ not working properly. This post being years old from now does tell me this is an issue that’s probably ArubaOS related.