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EX4100-48MP ignores PoE maximum-power command, misreads PoE class

  • 1.  EX4100-48MP ignores PoE maximum-power command, misreads PoE class

    Posted 08-21-2025 00:30

    We recently bought and setup 4 x EX4100-48MP switches, with almost the same configuration (main differences is number of ports assigned to each VLAN). 3 of the switches are working fine without incident, the 4th though is misreading the PoE Class requests from attached WAP devices and is coming up with crazy statistics such as consumed power six and a half kilowatts per PoE port! The same Ubiquiti WAPs work fine on the other 3 switches.

    {master:0}[edit]
    root@TSVCC-SW-G1-GLA2# run show poe interface
    Interface        Admin       Oper    Pair/Mode  Max        Priority       Power          Class
                                status         status  status            power                     consumption
    mge-0/0/0    Enabled      ON     SS/BT             30.0W      Low             6553.5W*       4/-
    mge-0/0/1    Enabled      ON     SS/BT             30.0W      Low             6553.5W*       4/-
    mge-0/0/2    Enabled      ON     SS/BT              30.0W      Low            6553.5W*       4/-
    mge-0/0/3    Enabled      ON     SS/BT              30.0W      Low            6553.5W*       4/-
    mge-0/0/4    Enabled      ON     SS/BT              30.0W        Low          6553.5W*       4/-
    mge-0/0/5    Enabled     OFF     SS/BT             15.4W      Low            0.0W           not-applicable

    compared to one of the 3 behaving switches...

    {master:0}
    root@TSVCC-SW-G0-Pantry> show poe interface
    Interface        Admin       Oper    Pair/Mode  Max        Priority       Power                  Class
                                status          status  status           power                            consumption
    mge-0/0/0    Enabled     OFF     SS/BT             15.4W      Low            0.0W           not-applicable
    mge-0/0/1    Enabled      ON     SS/BT              45.0W      Low            12.2W          5/-
    mge-0/0/2    Enabled     OFF     SS/BT             15.4W      Low            0.0W           not-applicable
    mge-0/0/3    Enabled      ON     SS/BT              45.0W      Low            11.9W          5/-
    mge-0/0/4    Enabled      ON     SS/BT             45.0W      Low            14.8W          5/-
    mge-0/0/5    Enabled      ON     SS/BT             45.0W      Low            12.7W          5/-
    mge-0/0/6    Enabled     OFF     SS/BT            15.4W      Low            0.0W           not-applicable

    noting different ports have different Max. Power settings with all the WAP ports showing as Class 5 / 45.0Watts, however on the misbehaving switch, they show as Class 4 .

    I have tried a global 

    poe {
        interface all;
    }

    as well as targetting individual ports through 

    poe {
        interface mge-0/0/2 {
            maximum-power 45.0;
        }
    }

    but the switch ignores the config PoE setting.

    Even funkier is if you look at the "Power over Ethernet (PoE) Configuration" page in J-Web portal, it shows conflicting PoE information on the same page!

    EX4100-48MP PoE Max Power

    I have tried various 23.x and 24.x versions of firmware, I have tried zeroising it, tried EZSetUp and setting up from scratch from USB media, always with the same result. If I swap 2 switches, the "weird stuff" follows the one switch. I swapped the power supply between 2 units, no change in outcome.

    So does anyone have idea what the hell is going on? Is it that the new switch is just faulty or is there some sorcery involved that I have encountered before?  Any ideas most welcome. Thanks. 



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