# deb http://ftp.ch.debian.org/debian/ stretch main deb http://ftp.ch.debian.org/debian/ stretch main non-free contrib deb-src http://ftp.ch.debian.org/debian/ stretch main non-free contrib deb http://security.debian.org/debian-security stretch/updates main contrib non-free deb-src http://security.debian.org/debian-security stretch/updates main contrib non-free # stretch-updates, previously known as 'volatile' deb http://ftp.ch.debian.org/debian/ stretch-updates main contrib non-free deb-src http://ftp.ch.debian.org/debian/ stretch-updates main contrib non-free