Ethernet connection issue, Wifi settings not holding

Installation
1

I’ve just set up Home Assistant on a RPi 3B and it boots up just fine. I wasn’t able to access it via the Ethernet connection, so I hooked up a kb/mouse/monitor and started with the CLI. I was able to set up a Wifi connection and I’m able to get into HA from my iPad and iPhone via Wifi.

BUT:

1-Seems like when it reboots, the Wifi settings are lost. How can I make this permanent? I would have thought that Wifi settings could be done via the UI under Settings, but not. [Yes, I would rather use a wired connection but see next question].

2-Ethernet doesn’t want to connect. I have a good connection (lights on the RPi port are what I would expect). Tried a different cable although both are known good cables. Connecting to a switch that my desktop computer is also hard-wired to. Checked my Router and there is no RPi wired connection. I ran “ip addr show” from the CLI and there is no IP4 address for the Ethernet port. See attached screen grab. Any idea why?

Thanks.

2025-03-05 20.18.12
2025-03-05 20.18.121920×1080 208 KB

2

Forgot to mention - I set the wifi up as static, both on the HA and in my router. When it reboots, it just doesn’t connect to wifi.

3

You could rule out the ethernet port by sticking Raspbian on another SD card and booting into that. If the ethernet port is fried it won’t work with that either.

4

OK, kind of strange answer here.

I ran a regular RPi OS on the board and it also didn’t connect to on the ethernet port. So I tried a crossover cable (I already tried 2 different cables from 2 different manufacturers) and the crossover cable worked!

Then I swapped the HA SD card back in (still with crossover cable) and ethernet is working.

I have the RPi connected to my usual 16 port Linksys switch like all my other wired ethernet devices so I shouldn’t need a crossover cable. But since it’s working, I’m not going to ask why.

Thanks.