[salmo]

I don’t think the other specs are necessarily backwards compatible. The NICs on each end negotiate the fastest commonly supported spec.

I’ve had 10G cards that would only negotiate down to 1G or only do 10G. But those were over Twinax. I’ve never use 10G on twisted pair.

Back in my day we were excited about 100Base-T and called it Fast Ethernet :).

Oooh! Now do 10Base2!

[thrtythreeforty]

Can confirm, we have a bunch of $10 switches lying around our million dollar lab because nobody thought to check if the 40Gbit switches can do 100Mbit to talk to Raspberry Pis. Not sure if we're ever pushing 40Gbit but I know we use the hell out of the RPis. Go figure...