Reverse polarity in "Link" tab

[wmnf90]

Hello all,

Hope this is the appropriate place to post this, and not an overly ridiculous question

I recently added a CSS610-8P-2S+IN to my home network, and I’m curious about what it means when the switch reports reverse polarity in cable pairs under the Link tab. I checked the wiki and searched the forums and Google, but couldn’t find a similar question.

The port to which a NUC is connected reports all 4 pairs have reversed polarity (screenshot attached). It’s consistent across different ports, odd and even. I don’t observe this if I use other cables with the NUC, nor when I use the same cable with other devices. The NUC is my only device with a 2.5GbE NIC, though I’m skeptical that it would affect anything, particularly since it doesn’t show it with other cables.

Does this even matter? Is this anything I should care about? It’s connected and it works, so I’m happy to stop obsessing over it if it’s just informational and not a problem status.

Thanks!

[k6ccc]

I had to look at the CSS610 series manual to figure out what you were talking about. All my switches are CSS326 or CSS106 series and they don’t have that indication.
However, with that said, it should not really matter as far as I know.
.

[jbl42]

Copper Ethernet is based on differential signals on twisted pairs. Those signals have +/- polarity which is detected between link partners on link establishment. Some chips (like 88E6193X in CSS610 and RB50009) can report the chosen polarity for a link as “normal” or “reversed”. It is just an indication and nothing to worry about.

[wmnf90]

Thank you both for the input! I’ll carry on ignoring it.