sudo aptitude update
Err http://mirrordirector.raspbian.org wheezy Release.gpg
  Temporary failure resolving 'mirrordirector.raspbian.org'
Err http://archive.raspberrypi.org wheezy Release.gpg
  Temporary failure resolving 'archive.raspberrypi.org'
Err http://raspberrypi.collabora.com wheezy Release.gpg
  Temporary failure resolving 'raspberrypi.collabora.com'
Err http://repository.wolfram.com stable Release.gpg
  Temporary failure resolving 'repository.wolfram.com'
W: Failed to fetch http://mirrordirector.raspbian.org/raspbian/dists/wheezy/Release.gpg: Temporary failure resolving 'mirrordirector.raspbian.org'
W: Failed to fetch http://raspberrypi.collabora.com/dists/wheezy/Release.gpg: Temporary failure resolving 'raspberrypi.collabora.com'
W: Failed to fetch http://archive.raspberrypi.org/debian/dists/wheezy/Release.gpg: Temporary failure resolving 'archive.raspberrypi.org'
W: Failed to fetch http://repository.wolfram.com/raspbian/dists/stable/Release.gpg: Temporary failure resolving 'repository.wolfram.com'
W: Some index files failed to download. They have been ignored, or old ones used instead.