Voici la Solution:
Il faut désactiver la connectivité IPv6 :
Running the following command in Terminal tells if IPv6 is enabled or not:
cat /proc/sys/net/ipv6/conf/all/disable_ipv6
0 means its enabled, while 1 means its disabled.
To disable IPv6 from within Terminal,
Solution 1 : sudo vim /etc/sysctl.conf
et ajouter les 4 lignes ci-dessous en fin de fichier.
Solution 2 : Entrer les commandes suivantes:
echo "#disable ipv6" | sudo tee -a /etc/sysctl.conf
echo "net.ipv6.conf.all.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf
echo "net.ipv6.conf.default.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf
echo "net.ipv6.conf.lo.disable_ipv6 = 1" | sudo tee -a /etc/sysctl.conf
sudo sysctl -p
Re-run the first command, and it should be 1 now.
Traduit de l’article : http://askubuntu.com/questions/272796/connecting-to-archive-ubuntu-com-takes-too-long