C9300-48P-A PoE power allocation

[ackman_liang]

We have multiple IOT PD devices connect to C9300, but they are detected as PoE class 3 device and C9300 allocate 15.4W of each port for each device.  We can only power up about 32 devices without redundant power supply.

The IOT device actually consumes about 3W, we used to configure C2960 or C3560 with "power inline consumption 5000" to limit the max power allocation of each port as 5W for this PoE class 3 device.

We are wondering to know whether we can limit the max power allocation of each port in C9300.

Is "power inline static max <max-wattage>" this right command in C9300 ?

[Leo Laohoo]

When a powered device is connected to A PORT on the switch, the switch (regardless of how much the device will actually consume) will ALWAYS push 15.4w.
Once the device boots up it then has the option to negotiate the actual power draw.
So if the device only uses 3w then the device will negotiate with the switch.
Power draw negotiation is done either using CDP or LLDP.

[ackman_liang]

Thanks for your reply. 

Since the device doesn't support CDP and LLDP, the negotiation is only based on IEEE 802.3at and the final negotiation result is PoE class 3.

We still want to confirm whether we can limit the power allocation regardless the negotiation result or not ?

Does there exist a configuration for C9300 (without redundant power supply) to power 48 PoE Class 3 PD devices which only draw less than 3W ?

[Reza Sharifi · Accepted solution]

The command is the same on the 9300

power inline static max <4000-60000>

HTH

[julian.bendix]

Hey!

yes - your command is correct!

Just please be aware, exactly as with the "old" command you used on Cat2960,
it will be the same on the Cat9300 Series with the new command:

With "#power inline static mac 5000" in Interface Config,
you will permanenty reserve 5W for this port.

That means 5W will be constantly subtracted from your power pool.

Other than that, you are good to go!

Let me know if you need anything else.

Best regards :)

P.S. please mark helpful posts or the solution if your question is resolved