Temporary failure resolving 'us.archive.ubuntu.com'
Reading package lists... Done
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/natty/InRelease

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/natty-updates/InRel
ease

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/natty-security/InRele
ase

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/natty-security/Releas
e.gpg  Temporary failure resolving 'security.ubuntu.com'

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/natty/Release.gpg
Temporary failure resolving 'us.archive.ubuntu.com'

W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/natty-updates/Relea
se.gpg  Temporary failure resolving 'us.archive.ubuntu.com'

W: Some index files failed to download. They have been ignored, or old ones used
 instead.