I have a port (all wiring is T568A) to my son’s room. My work laptop connects fine. No issues. I can see IPV4 and 6 addresses, DNS etc. His desktop will not connect. Only shows IP6. No IP4, no DNS. We have tried swapping the cable to his desktop and it still makes no different.
Any ideas where to start troubleshooting?
Flash a linux live usb and boot from it. see if it can auto negotiate, so you know if it is a software problem or a hardware problem