I have problems when trying to update the apt repositories.
pi@raspberrypi:~ $ sudo apt-get update
Err http://mirrordirector.raspbian.org jessie InRelease
Err http://mirrordirector.raspbian.org jessie Release.gpg
W: Some index files failed to download. They have been ignored, or old ones used instead.
ping www.google.com
to see if you are connected to the network or not.