-*- outline -*-* Conf files.See man sources.list(5), apt.conf(5). /etc/apt/sources.list /etc/apt/apt.conf* Setup backport.Main backports archive you can find on www.backports.org.To get packeges gpg sign key: $ su ... $ wget -O - http://backports.org/debian/archive.key | apt-key add - $ ^DWrite where packeges places: $ cat /etc/apt/sources.list deb cdrom:[Debian GNU/Linux 4.0 r0 _Etch_ - Official amd64 DVD Binary-2 20070407-12:15]/ etch contrib main deb cdrom:[Debian GNU/Linux 4.0 r0 _Etch_ - Official amd64 DVD Binary-1 20070407-12:15]/ etch contrib main deb http://www.backports.org/debian/ etch-backports main contrib non-free* Getting new keys for packages. $ sudo apt-get update...W: There is no public key available for the following key IDs:9AA38DCD55BE302BW: GPG error: http://http.us.debian.org etch Release: The following signaturescouldn't be verified because the public key is not available: NO_PUBKEY9AA38DCD55BE302B... $ gpg --keyserver pgp.mit.edu --recv-key 9AA38DCD55BE302B \--keyserver-options http-proxy=http://user:pass@192.168.1.1:3128gpg: requesting key 55BE302B from hkp server pgp.mit.edugpg: key 55BE302B: public key "Debian Archive Automatic Signing Key (5.0/lenny) <ftpmaster@debian.org>" importedgpg: no ultimately trusted keys foundgpg: Total number processed: 1gpg: imported: 1 (RSA: 1) $ gpg --export 9AA38DCD55BE302B | sudo apt-key add -OK