I work many days a week in the office building where I’ve set the robot vacuums up to fight to the death. It’s a multi-tenant office building where many of the tenants receive shared internet as part of their rent via wireless and wired connections.
TL;DR – USB C to ethernet dongle very useful
The wired, I’m surprised at how many things have gone wrong or can go wrong. These problems are mainly at the plug ends, and not the existing wiring, but sometimes someone plugs a blender in and everything goes to hell.
Mostly however the complaints start with “speed is too slow on ethernet” and quite often end with replacing a jack that has degraded. They do that. I didn’t know how often wall jacks degrade until it started happening on a regular basis (really, you deal with 92 wall jacks on a regular basis you’re going to see this eventually.)
In the past to diagnose these it’s been go to office, fire up ancient laptop, head to tenant’s office, plug in, hope ancient laptop booted, oh it didn’t, wait, test.
With a little USB C to ethernet dongle I pop it on my phone, plug it in, and can Speedtest within 2 seconds.
I always have my phone on me, and now just a little pocketable piece of equipment allows me to test ports, packet sniff (app required,) and verify what is actually at fault.
I got this one, but have no comparison to others so don’t take this as a shining recommendation
It worked with my Samsung Galaxy S21 Ultra 5G right out of the box and no configuration needed. Just all internet goes over it when plugged into an ethernet source, back to Wi-Fi or cell if the ethernet cable is unplugged. Indicator on screen and verified with whatismyip.com