Reservation of PoE

[s.hellman]

The cisco switch has a PoE budget of 195w and the AP's draws about 15-17w, so it should be possible to connect at least 11 AP's.

This works fine with HPE and Huawei switches, but with cisco switches it reserves 30w per AP so we can only get 6 AP's running.

Is there any way to get around this? We have tried to limit power on the switch ports with 'Power inline comsumption xxxx' but that is resulting that the AP's run with reduced performance.

[Leo Laohoo · Accepted solution]

Read THIS.

static—The switch pre-allocates power to the port (even when no powered device is connected) and guarantees that power will be available for the port. The switch allocates the port configured maximum wattage, and the amount is never adjusted through the IEEE class or by CDP messages from the powered device. Because power is pre-allocated, any powered device that uses less than or equal to the maximum wattage is guaranteed to be powered when it is connected to the static port. The port no longer participates in the first-come, first-served model. 

However, if the powered-device IEEE class is greater than the maximum wattage, the switch does not supply power to it. If the switch learns through CDP messages that the powered device is consuming more than the maximum wattage, the switch shuts down the powered device. 

If you do not specify a wattage, the switch pre-allocates the maximum value. The switch powers the port only if it discovers a powered device. Use the static setting on a high-priority interface.

[s.hellman]

Great workaround, thanks Leo.

Power inline consumption 17000

Power inline static max 17000

Now the AP's run at "Full power", although the switch only reservs 17w.

We still have to configure all the AP-connected ports though, would have been nice if there were a global command to disable the behaviour. As I said, other brand of switches dont do like this, but this will be ok.