Solving the Ubuntu 12.04 Update Error: (-5 - No address associated with hostname) [duplicate]

Problem Description:

Each time i try to download the updates for my operating system (Ubuntu 12.04) i get the following list of error messages:

W:Failed to fetch http://extras.ubuntu.com/ubuntu/dists/precise/Release.gpg  Something wicked happened resolving 'extras.ubuntu.com:http' (-5 - No address associated with hostname)
, W:Failed to fetch http://ppa.launchpad.net/deluge-team/ppa/ubuntu/dists/precise/Release.gpg  Something wicked happened resolving 'ppa.launchpad.net:http' (-5 - No address associated with hostname)
, W:Failed to fetch http://packages.medibuntu.org/dists/precise/Release.gpg  Something wicked happened resolving 'packages.medibuntu.org:http' (-5 - No address associated with hostname)
, W:Failed to fetch http://archive.canonical.com/ubuntu/dists/precise/Release.gpg  Something wicked happened resolving 'archive.canonical.com:http' (-5 - No address associated with hostname)
, W:Failed to fetch http://ppa.launchpad.net/tualatrix/ppa/ubuntu/dists/precise/Release.gpg  Something wicked happened resolving 'ppa.launchpad.net:http' (-5 - No address associated with hostname)
, E:Some index files failed to download. They have been ignored, or old ones used instead.

The Contents of (/etc/apt/sources.list) File:

# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release i386 (20120423)]/ precise main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://archive.ubuntu.com/ubuntu precise main restricted
deb-src http://archive.ubuntu.com/ubuntu precise main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu precise-updates main restricted
deb-src http://archive.ubuntu.com/ubuntu precise-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu precise universe
deb-src http://archive.ubuntu.com/ubuntu precise universe
deb http://archive.ubuntu.com/ubuntu precise-updates universe
deb-src http://archive.ubuntu.com/ubuntu precise-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://archive.ubuntu.com/ubuntu precise multiverse
deb-src http://archive.ubuntu.com/ubuntu precise multiverse
deb http://archive.ubuntu.com/ubuntu precise-updates multiverse
deb-src http://archive.ubuntu.com/ubuntu precise-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.

deb http://archive.ubuntu.com/ubuntu precise-security main restricted
deb-src http://archive.ubuntu.com/ubuntu precise-security main restricted
deb http://archive.ubuntu.com/ubuntu precise-security universe
deb-src http://archive.ubuntu.com/ubuntu precise-security universe
deb http://archive.ubuntu.com/ubuntu precise-security multiverse
deb-src http://archive.ubuntu.com/ubuntu precise-security multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu precise partner
# deb-src http://archive.canonical.com/ubuntu precise partner

## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu precise main
# deb-src http://extras.ubuntu.com/ubuntu precise main

The Files inside of (/etc/apt/sources.list.d) directory:

-rw-r--r-- 1 root root 136 Oct 10 16:30 deluge-team-ppa-precise.list    
-rw-r--r-- 1 root root 136 Oct 10 16:30 deluge-team-ppa-precise.list.save         
-rw-r--r-- 1 root root 285 Oct 10 16:30 medibuntu.list        
-rw-r--r-- 1 root root 285 Oct 10 16:30 medibuntu.list.save          
-rw-r--r-- 1 root root 132 Oct 10 16:30 tualatrix-ppa-precise.list         
-rw-r--r-- 1 root root 134 Oct 10 16:30 tualatrix-ppa-precise.list.save          
-rw-r--r-- 1 root root 148 Oct 10 16:30 yannubuntu-boot-repair-precise.list       
-rw-r--r-- 1 root root 148 Oct 10 16:30 yannubuntu-boot-repair-precise.list.save  

Related Links to this Post on AskUbuntu.com:

Server error (-5 - No address associated with hostname)
How to fix "-5 No address associated with hostname error" while updating?

I have tried to research online for ways to solve the issue but i failed to figure out the real reason why i am getting those errors. Any suggestions, ideas or solutions that might aid me to solve this issue are greatly appreciated.


The solution to this problem goes as follows:

Step 1: Go to System –> Preferences –> Network Connections.

Step 2: Next, select your default Network Interface (eth0) and click ‘Edit’.

Step 3: Then select ‘IPv4 Settings’ and choose ‘Automatic (DHCP) addresses only’.

Step 4: Next, enter the new DNS server addresses in the ‘DNS servers’ box. Use commas to separate multiple addresses and click ‘Apply’ to save.

Step 5: Choose your preferred DNS details

OpenDNS           --->  208.67.222.222, 208.67.220.220              
Google Public DNS --->  8.8.8.8, 8.8.4.4                 
Comodo Secure DNS --->  156.154.70.22, 156.154.71.22

After configuring, check to make sure it is working by going online.

For full step-by-step tutorial for solving similar problems please check:
http://www.liberiangeek.net/2010/08/change-dns-information-ubuntu-10-04-lucid-lynx/

The above link explains how to change the DNS Settings in Ubuntu.


I had this same problem and none of the above answers fixed it. I DO have it fixed now however. Turns out all I needed to do was go into terminal and type sudo apt-get update . After it finished running, my update manager refreshed, gave me a new list of items to update and then I clicked update and everything ran fine. Don't know if this will help anyone else, but I hope it does.


cat /etc/apt/sources.list 

edit with

sudo gedit /etc/apt/sources.list

delete http://packages.medibuntu.org/

then run

sudo apt-get update