OK, it was indeed simple and stupid!
It was one of the adaptors, just not the one that I had changed out! Finally at my wits end replaced it with one of the ones I had mistakenly swapped out, and everything is fine. Anyway, an instructive unguided tour of the wilds of modern networking, which is a lot more complicated than in my youth. Or at least different.
Now for the next challenge, converting a bios system to efi. I have put together a system using Aorus from Gigabyte. It does not support legacy mode. At least it boots normally from an EFI stick so the build is OK. The next step will be to convert the cloned bios drive to EFI
By the way, if anyone ever wants to clone a hard drive I strongly recommend foxclone. Absolutely brilliant, simple and foolproof. If you ever got tired and irritable wandering through the thickets of clonezilla you will love foxclone. Its a lot faster than CZ, and it will also clone a large drive to a smaller one, assuming there is space for all the files.
Peter
Also systemctl status NetworkManager gives this:
NetworkManager.service - Network Manager Loaded: loaded (/lib/systemd/system/NetworkManager.service; enabled; preset: enabled) Active: active (running) since Wed 2023-12-20 16:53:00 GMT; 1h 39min ago Docs: man:NetworkManager(8) Main PID: 769 (NetworkManager) Tasks: 3 (limit: 19064) Memory: 14.1M CPU: 545ms CGroup: /system.slice/NetworkManager.service
So that's working. I have come on the suggestion to disable it and then configure /etc/network/interfaces manually. What do you think?
Peter
Puzzle about networking. Any suggestions?
All of a sudden and for no apparent reason my ethernet connection isn't working. Its not the router, other machines on the router work fine. Its not the local powerline device, I have changed that out. The machine also works fine with a mobile data dongle plugged in to a usb port. So I think it must be something about the configuration, though why it should suddenly have changed is a mystery to me.
I do ip link, and this shows as number two:
2: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000 link/ether 08:60:6e:e7:d2:be brd ff:ff:ff:ff:ff:ff
So then I do ifup enp3s0, and get this:
~$ sudo ifup enp3s0 ifup: unknown interface enp3s0
When I use the gnome network control tool it fails to bring it up.
ip link set appears to work, at least no error message.
ifconfig gives this:
enp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet6 fe80::d2da:494:eadc:4e0b prefixlen 64 scopeid 0x20<link> ether 08:60:6e:e7:d2:be txqueuelen 1000 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 982 bytes 158082 (154.3 KiB) TX errors 1 dropped 0 overruns 0 carrier 0 collisions 0
So why can't I bring it up with ifup?
Rebooting doesn't make any difference. I don't know what else to try. Its probably something very simple that I am just missing....
Peter