root@server:~# apt-get update
Err:1 http://ftp.debian.org/debian buster InRelease
Temporary failure resolving 'ftp.debian.org'
Err:2 http://security.debian.org/debian-security buster/updates InRelease
Temporary failure resolving 'security.debian.org'
Err:3 http://download.proxmox.com/debian/pve buster InRelease
Temporary failure resolving 'download.proxmox.com'
Err:4 http://ftp.debian.org/debian buster-updates InRelease
Temporary failure resolving 'ftp.debian.org'
Reading package lists... Done
W: Failed to fetch http://ftp.debian.org/debian/dists/buster/InRelease Temporary failure resolving 'ftp.debian.org'
W: Failed to fetch http://ftp.debian.org/debian/dists/buster-updates/InRelease Temporary failure resolving 'ftp.debian.org'
W: Failed to fetch http://download.proxmox.com/debian/pve/dists/buster/InRelease Temporary failure resolving 'download.proxmox.com'
W: Failed to fetch http://security.debian.org/debian-security/dists/buster/updates/InRelease Temporary failure resolving 'security.debian.org'
W: Some index files failed to download. They have been ignored, or old ones used instead.
W: Target Packages (pve-no-subscription/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list.d/pve-no-subscription.list:1
W: Target Packages (pve-no-subscription/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list.d/pve-no-subscription.list:1
W: Target Translations (pve-no-subscription/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list.d/pve-no-subscription.list:1
W: Target Translations (pve-no-subscription/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:6 and /etc/apt/sources.list.d/pve-no-subscription.list:1