Here is a quick tip to add an official Debian CD disk to your /etc/apt/sources.list file to reduce package download requirement. Make sure that your CD is inserted to your CD-ROM drive and enter command:
# apt-cdrom add
If for example you are adding Wheezy image the below output will be generated:
Using CD-ROM mount point /media/cdrom/ Identifying.. [6736485c3d92e1c9e5a024828c9283a2-2] Scanning disc for index files.. Found 1 package indexes, 0 source indexes, 1 translation indexes and 0 signatures This disc is called: 'Debian GNU/Linux 7.5.0 _Wheezy_ - Official amd64 CD Binary-1 20140426-13:37' Reading Package Indexes... Done Reading Translation Indexes... Done Writing new source list Source list entries for this disc are: deb cdrom:[Debian GNU/Linux 7.5.0 _Wheezy_ - Official amd64 CD Binary-1 20140426-13:37]/ wheezy main
This will add:
deb cdrom:[Debian GNU/Linux 7.5.0 _Wheezy_ - Official amd64 CD Binary-1 20140426-13:37]/ wheezy main
line into your /etc/apt/sources.list file.