from https://askubuntu.com/questions/32298/prefer-a-ipv4-dns-lookups-before-aaaaipv6-lookups
# For sites which prefer IPv4 connections change the last line to # precedence ::ffff:0:0/96 100 # # For sites which use site-local IPv4 addresses behind NAT there is # the problem that even if IPv4 addresses are preferred they do not # have the same scope and are therefore not sorted first. To change # this use only these rules: # scopev4 ::ffff:169.254.0.0/112 2 scopev4 ::ffff:127.0.0.0/104 2 scopev4 ::ffff:0.0.0.0/96 14