Forcing apt-get to use IPv4
When or if you run into trouble with apt-get and IPv6 connections timing out or not resolving properly at all, it may be a good idea to simply prevent apt-get from using IPv6. Use -o Acquire::ForceIPv4=true when running apt-get, or create /etc/apt/apt.conf.d/99force-ipv4 and put Acquire::ForceIPv4 …