[bombcar]

Many of those variations of ethernet remain compatible, 10g switches can often negotiate down to 10/100.

[eru]

Yes. And the replacement to git might also stay compatible.

(In an extreme case, git can talk svn via git-svn. In a weird alternative history, you could imagine git being treated as a new version of svn; but apart from the names, nothing much else would change compared to our universe.)

[yardie]

I’ve worked with many switches. I have not encountered a 10g switch that will negotiate to 10m. 100m is not automatic in most cases. These very old protocols are very different from modern 10g-100g. So much so that the transceivers may need to load a completely different firmware to even understand it.

[bombcar]

100g may be too high, but my micro tick does fine: https://mikrotik.com/product/s_rj10

(I’ve not seen 100g over copper, but 10g is doable)

I don’t know if it will go down to half duplex.

[yardie]

Ok. Most of my experience the switches will have 2 modes for each port: 1G/2.5G/10G/25G/100G or 10M/100M/1G/2.5G. This is typical for datacenter switches. Found this out when my trusty 10/100M USB dongle couldn't establish link. I needed to upgrade to a 1G USB3 dongle.

[bombcar]

Now I want a datacenter switch with a gearshift for speeds, "high", "low" and "turbo" perhaps.

[toast0]

Half duplex is in spec at 100 as well as 10, so I'd be surprised if it didn't.