apt-get name resolution error

Question

I just typed in the sudo apt-get update and I'm getting the following error:

Err http://de.archive.ubuntu.com natty InRelease

Err http://security.ubuntu.com natty-security InRelease

Err http://de.archive.ubuntu.com natty-updates InRelease

Err http://security.ubuntu.com natty-security Release.gpg
  Temporary failure resolving 'security.ubuntu.com'
Err http://de.archive.ubuntu.com natty Release.gpg
  Temporary failure resolving 'de.archive.ubuntu.com'
Err http://de.archive.ubuntu.com natty-updates Release.gpg
  Temporary failure resolving 'de.archive.ubuntu.com'
Reading package lists... Done
W: Failed to fetch http://de.archive.ubuntu.com/ubuntu/dists/natty/InRelease  

W: Failed to fetch http://de.archive.ubuntu.com/ubuntu/dists/natty-updates/InRelease  

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

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

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

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

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

Answer 1

Temporary failure resolving 'de.archive.ubuntu.com'

This is indicative of a DNS problem. Make sure your DNS servers are set correctly on the client and verify that the servers are actually functioning as they ought to be.