Post #2309513

2023-04-07 22:27 UTC

In the no question is too stupid to ask and forgiving my authorship of a half-dozen books on the subject of Ethernet and its uses, I have a question. If you are feeding power over Ethernet (POE) into devices that don&#39;t use POE, you can&#39;t hurt them, right? (I have POE ports and non-POE ports on my switches, but do I care if a hot cable goes into a device that doesn&#39;t need or use it?)

Replies (5)

@virtuous_sloth@mstdn.ca 2023-04-07 22:32

@carlmalamud@official.resource.org The power is negotiated I think, so there is never a problem with the case you describe.

Open ##2980003
@danlyke@researchbuzz.masto.host 2023-04-07 22:33

@carlmalamud@official.resource.org I believe that to be the case enough that I have several non-powered devices plugged into a powered hub on my home network, and haven't had smoke come out of them yet. And it's been a few years.

Open ##2980004
@kevin@mastodon.km6g.us 2023-04-08 00:10

@carlmalamud@official.resource.org As other replies have indicated there's no 'feeding' from the PSE unless there is a PD asking for it.

Open ##2980007
@jimfenton@mastodon.social 2023-04-08 03:41

@carlmalamud@official.resource.org Some older PoE implementations don’t negotiate, so that could be a problem for some devices. I have a Hubitat hub that says not to plug it into a PoE port, but I don’t know if that’s a limitation or out of an abundance of caution (not knowing what PoE flavor it is).

Open ##2980008
@Ccollet@blander.ddnsfree.com 2023-04-08 12:56

@carlmalamud@official.resource.org supposedly it's only a problem for really old, weird equipment. But I literally have a PDP-11 plugged into my POE switch and it works fine... so 🤷

Open ##2980016