comments:
craigrpeters posted on r/ethernet10h
Look at YouTube vids on how to make Ethernet connections. It’s easier to watch than to explain it and there’s hundreds of videos available. Best guess is someone didn’t wire it up right - could be bad connections, or the 8 wires weren’t put into the right slots on each end. Might even be the wires weren’t put into cut if there’s been major reno work. Look into getting a continuity tester - they are cheap and tailored for troubleshooting Ethernet, eg something like this: TESMEN TLP-123A Network Cable Tester for RJ11 RJ45, Ethernet Wire Tool for CAT5/CAT5E/CAT6/CAT6A/CAT7/UTP&STP, LAN & TEL Continuity Test, Suitable for Cable Maintenance - Green. https://a.co/d/0fFut9SJ