David Christensen wrote on Wed, 31 Mar 2021 13:49:56 -0700: I would do 'apt-get update' and 'apt-get upgrade' ('autoremove', 'clean', etc.). Once apt-get(8) is done, I would revert the changes to /etc/resolv.conf and see if name resolution breaks or remains working. (I would test by renaming /etc/resolve.conf and rebooting.)
Here is what I did: # apt update # apt upgrade # apt autoremove # apt-get clean # cp /etc/resolv.conf /etc/resolv.confX # chattr -i /etc/resolv.conf ## to make resolv.conf *not* immutable # cat /etc/resolv.conf domain attlocal.net search attlocal.net nameserver 1.1.1.1 nameserver 1.0.0.1 nameserver 192.168.1.254 Shutdown then power-on boot ## rebooted with /etc/resolv.conf *not* immutable root@deb4:~# ping google.com ping: google.com: Temporary failure in name resolution root@deb4:~# cat /etc/resolv.conf domain attlocal.net search attlocal.net nameserver 192.168.1.254 ## showing that /etc/resolv.conf has been clobbered After restoring resolv.conf so that it looks like this: # cat /etc/resolv.conf domain attlocal.net search attlocal.net nameserver 1.1.1.1 nameserver 1.0.0.1 nameserver 192.168.1.254 # chattr +i /etc/resolv.conf ## making it immutable Rebooted and posted this. - Dan