Merhabalar, root olarak giriş yaptıktan sonra debian sunucuya apt-get update komutu ile update yapmaya çalışıyorum. aşağıdaki hatayı alıyorum. bilgisi olanlar yardımcı olabilirmi?

apt-get update
Err http://security.debian.org jessie/updates InRelease

Err http://ftp.debian.org jessie-updates InRelease

Err http://security.debian.org jessie/updates Release.gpg
Could not resolve 'security.debian.org'
Err http://ftp.debian.org jessie-updates Release.gpg
Could not resolve 'ftp.debian.org'
Err http://ftp.us.debian.org testing InRelease

Err http://ftp.us.debian.org testing Release.gpg
Could not resolve 'ftp.us.debian.org'
Reading package lists... Done
W: Failed to fetch http://ftp.us.debian.org/debian/dists/testing/InRelease

W: Failed to fetch http://ftp.debian.org/debian/dists/jessie-updates/InRelease

W: Failed to fetch http://security.debian.org/dists/jessie/updates/InRelease

W: Failed to fetch http://security.debian.org/dists/jessie/updates/Release.gpg Could not resolve 'security.debian.org'

W: Failed to fetch http://ftp.debian.org/debian/dists/jessie-updates/Release.gpg Could not resolve 'ftp.debian.org'

W: Failed to fetch http://ftp.us.debian.org/debian/dists/testing/Release.gpg Co uld not resolve 'ftp.us.debian.org'

W: Some index files failed to download. They have been ignored, or old ones used instead.