Ethernet connection showing no connection

The internet is not working on my 2017 iMac desktop. Wi-Fi works fine; when I try to connect via ethernet cable, it shows no connection. Tried new cable, using cable that works on other desktop, still no connection. Router is functioning normally and says it is sending info to the desktop. Desktop iMac still says no ethernet cable connected. OS Ventura 13.7.8 is latest I can get.