Fairy new to the ethernet game, but I just re-terminated one of my cat6 runs from a RJ45 plug to a punch-down keystone jack. My understanding is this is a superior way to terminate pure copper cables, so now I have the patch panels and other gear I’ve been starting to do that in various places.

Once plugged back in, my switch negotiated the connection to 100Mbs, instead of 1Gbs as previously. This isn’t a major problem as I can switch the port to 1Gbs manually, which I have done and which has worked. But it begs the question, have I messed up the punch-down termination? Should I do it again?

I’m interested in some of the detail about how this works here. How does the switch determine what speed to auto-negotiate to? And what kind of physical factors come into play?

Thanks.

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