Does the M4300-28G-PoE+ support PoE 802.3af with variant A or B, or maybe both? A or B refers to https://en.wikipedia.org/wiki/Power_over_Ethernet#Pinouts I have PoE device which in particular requires PoE 802.3af variant A (+DC on pin 1 and 2, -DC on pin 3 and 6), and want to know, if it will work with this switch (that device is Ubiquiti UniFi Mesh UAP-AC-M).

I have 2 UAP-AC-M-PRO connected to a M4300-28G-PoE+, yes this is the bigger model that only supports 802.3af but I can say that this particular model does work as expected. Other than that I agree with schumaku concerning the sensing that happens with PoE. It gets even more complex with PoE+... ;)

Thank You for a quick reply, but I still have doubts. This device (UniFi AP) supports passive PoE, as stated in datasheet: 24V Passive PoE (Pairs 4, 5+; 7, 8 Return) 802.3af Alternative A (Pairs 1, 2+; 3, 6 Return) So if switch will power device on pins 4,5;7,8 (variant B), may not detect it properly, or even damage by putting 50V, where 24V is expected. If switch puts power on pins 1,2;3,6, then all should be fine. That's why is so important for me, which variant is implemented. As a last resort solution is possible to connect device with only 1,2,3,6 pins, but then connection speed will be down to 100Mbit, what i want to avoid.

Hi, I believe this access point supports both Passive 24V ou Active 802.3af PoE modes and any standard PoE switch will work just fine in standard 802.3af mode. As such, the M4300 switches should be OK. I hope this will help, Regards,

I think the access point manufacturer datasheet is leading to some confusion, and I can attest you will find many reports and feedback on other forums with this access point working fine with perfectly standard 802.3af switches.

Thank You. I'll get the mentioned hardware in about month or so, then report back.

PoE 802.3af Standards A or B | NETGEAR Communities

15 Replies

LaurentMa
NETGEAR Expert
May 16, 2019
Hi,

I believe this access point supports both Passive 24V ou Active 802.3af PoE modes and any standard PoE switch will work just fine in standard 802.3af mode. As such, the M4300 switches should be OK.

I hope this will help,

Regards,
- WojtekC
  Guide
  May 16, 2019
  Thank You for a quick reply, but I still have doubts.
  
  This device (UniFi AP) supports passive PoE, as stated in datasheet:
  
  24V Passive PoE (Pairs 4, 5+; 7, 8 Return)
  
  802.3af Alternative A (Pairs 1, 2+; 3, 6 Return)
  
  So if switch will power device on pins 4,5;7,8 (variant B), may not detect it properly, or even damage by putting 50V, where 24V is expected.
  
  If switch puts power on pins 1,2;3,6, then all should be fine. That's why is so important for me, which variant is implemented.
  
  As a last resort solution is possible to connect device with only 1,2,3,6 pins, but then connection speed will be down to 100Mbit, what i want to avoid.
  - LaurentMa
    NETGEAR Expert
    May 16, 2019
    I think the access point manufacturer datasheet is leading to some confusion, and I can attest you will find many reports and feedback on other forums with this access point working fine with perfectly standard 802.3af switches.