C3850 Power Inline / UPOE Question

[Brian Maxwell]

Hello,

We have some C3850 switches all of which have sufficient power supplies to support UPOE.  I have a couple questions about the configuration of POE.

1. Is there anything special I need to do to enable the UPOE functionality or does it just happen?

2.  Is there a comprehensive list somewhere of all the Cisco IOS commands and their descriptions?  I've read: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/16-3/configuration_guide/b_163_consolidated_3850_cg/b_163_consolidated_3850_cg_chapter_01011011.html but it doesn't explain what things like 'POE High Availability' actually mean.

Thank you!

[Leo Laohoo]

uPoE is hardware specific. If the model of the switch doesn't support uPoE then it the most the switch can do is PoE+ or 30.0w.

[Brian Maxwell]

Understood.  Our models do support it.  They are:

WS-C3850-48U

WS-C3850-24U

I'm wondering if there's special configuration considerations.

Thanks,

[Leo Laohoo]

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@Brian Maxwell wrote:

Understood.  Our models do support it.  

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There's really no "special consideration".  uPoE is enabled by default and the ports regulate the power downstream automatically (by default).  

How-much-power-per-port or how-many-uPoE ports is solely depend on how much power is available and subjected first-come-first-serve-until-exhausted.  

Let's say the output to the command of "sh power inline" gives 1000w power allowance.  This will mean that this power "allowance" is given to anyone who requests power until there is no longer enough or no longer left.  There's no "uPoE has first priority".

For power redundancy, there are two ways around this: 

1.  Extra power supply; and 

2.  Power stacking. 

3850 supports both.  Power stacking means the switch can take the power of another switch in a stack as long as the stack is connected to a power stack (not a stacking cable).

Does this make any sense?

[Brian Maxwell]

Thank you.  That makes sense.