topic Re: X450-G2 Can't it supply Class 7 POE? in ExtremeSwitching (EXOS/Switch Engine)

X450-G2 Can't it supply Class 7 POE?

Keith9 — Tue, 03 Feb 2026 15:23:48 GMT

We are replacing Cisco Access points (3802i) with Juniper Mist AP36. The Juniper console is showing two ap's at one of our sites in reduced functionality mode due to POE. In other sites these are looking fine with Class 7 POE displayed (5220 switch stacks).

This is a two switch 48 port poe 450G2 stack, each switch with dual power supplies. I've reset the port and also added this line just in case:
configure lldp port 2:23 advertise vendor-specific dot3 power-via-mdi with-classification

Still only showing class 4.
How can I get this to do class 7 poe?

sh power
PSU-1 or PSU-2 or
Internal External External External Power
Slots Type PSU PSU PSU PSU Usage
------ ------------------------------- --------- --------- --------- --------- ------
Slot-1 X450G2-48p-10G4 P P - - 114.94
Slot-2 X450G2-48p-10G4 P P - - 125.93

sh inline-power

Inline Power System Information
Configured : Enabled
Power Usage Threshold : 70 percent (per slot)
Disconnect Precedence : deny-port
Inline Power budget : Maximum
Budgeted Measured
Slot Inline-Power Firmware Status Power (Watts) Power (Watts)
1 Enabled Operational 1021 W 31 W
2 Enabled Operational 1021 W 41 W

sh inline-power stats ports 2:23

STATISTICS COUNTERS
Port State Class Absent InvSig Denied OverCurrent Short
2:23 delivering class4 1 28 0 0 0

configure lldp port 2:23 advertise system-capabilities
configure lldp port 2:23 advertise vendor-specific dot3 power-via-mdi with-classification
configure lldp port 2:23 advertise vendor-specific med capabilities
configure lldp port 2:23 advertise vendor-specific med power-via-mdi
configure lldp port 2:23 advertise vendor-specific med policy application voice vlan VOICE dscp 46

AP's working but according to Juniper Mist it says
Power Source: LLDP
Power Request Count: 1
Power Allocated: 25.5 W
Power Requested: 25.5 W
Power Required: 27.9 W
Operating Mode: 5 GHz (4x4), 6 GHz (2x2), 2.4 GHz (2x2).

On another site that works the Juniper system says that the Power Allocated, Requested and Required are all 27.9 W and operating mode is "Full Power".

Re: X450-G2 Can't it supply Class 7 POE?

Gabriel_G — Wed, 04 Feb 2026 14:30:02 GMT

The x450-G2-48P models support 802.3af PoE up to Class 4 (30W).
This is generally true for all 'P' model switches.
https://documentation.extremenetworks.com/summit_16/downloads/SummitFamily_HW_Install.pdf

The 5520-48W models support 802.3bt PoE up to Class 8 (90W).
This is generally true for all 'W' model switches.
https://documentation.extremenetworks.com/5520%20Series%20Installation%20Guide/downloads/5520_Series_Installation_Guide.pdf

Some devices require more LLDP advertisements for software-based classification:
https://extreme-networks.my.site.com/ExtrArticleDetail?an=000089716

Hope that helps!

Re: X450-G2 Can't it supply Class 7 POE?

JPR — Wed, 04 Feb 2026 14:37:06 GMT

An X450G2-48p supports POE+ IEEE 802.3at class 4 - up to 30W per port - class 7 POE++ is not available on this Switch Typ.

But I checked that the Juniper Mist AP36 only needs only POE+?? ...ask Juniper about this problem.

https://www.juniper.net/documentation/us/en/software/mist/mist-wireless/topics/ref/ap-poe-requirements.html

Re: X450-G2 Can't it supply Class 7 POE?

Keith9 — Wed, 04 Feb 2026 14:38:04 GMT

Ok so odd class 4 claims 30W, the device wants 27 but the switch can only put out 25. Where's my other 5 Watts I paid for?
The only thing it does is make 6 GHz wifi 2x2 MIMO instead of 4x4. Not a great loss. Most of our stuff is 5 GHz anyway and they keep that at 4x4.

The 450G2 I think goes end of service life in January 2028 so we'll budget to replace 3 of our sites that have them by that date. All of our other sites have 5520's. I don't think we'll bother with injectors just for 4x4 6 Ghz.

Re: X450-G2 Can't it supply Class 7 POE?

Keith9 — Thu, 05 Feb 2026 22:32:01 GMT

They do work on POE+, they just reduce the 6 GHz radio from 4x4 MIMO to 2x2 MIMO. Thats an ok tradeoff as they keep 5 GHz at 4x4. None of our wifi adapters are more than 2x2 in 6 GHz and we do not have a very large number of clients.

The AP36 requests 27.9 Watts of power, but the X450G2 can only deliver 25 .5 Watts so it drops down that 6 GHz radio.
Most of our sites have 5520 switches and they operate at full power. Just 3 of our sites are on the older generation switches.

Re: X450-G2 Can't it supply Class 7 POE?

Stefan_K_ — Fri, 06 Feb 2026 16:59:00 GMT

Thats just how the PoE+ Standard is defined.

Power available at PD 25.50W

Maximum power delivered by PSE 30.0W

Thats why PoE++ is required for all Features of this AP. 27W is simply not possible with PoE+.