IPv4 Over IPv6
All of the new installation that I have done here lately set IPv6 as the preferred IP stack. Which in turn cause problems for me. I have noticed that my Debian systems update at a crawl when using the Debian IPv6 mirrors.
Sitting IPv4 as the preferred IP stack is rather simple.
Uncomment the line below in file: /etc/gai.conf
precedence ::ffff:0:0/96 100