Hello,
mirrorlist.centos.org currently doesn't correctly answer on IPv6 - The request succeeds superficially (200 OK), but the answer is empty:
~ $ curl -6 "http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os" ~ $ curl -4 "http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os" http://mirror.ibcp.fr/pub/Centos/6.6/os/x86_64/ http://distrib-coffee.ipsl.jussieu.fr/pub/linux/centos/6.6/os/x86_64/ http://mirror1.babylon.network/centos/6.6/os/x86_64/ ftp://ftp.free.fr/mirrors/ftp.centos.org/6.6/os/x86_64/ http://centos.quelquesmots.fr/6.6/os/x86_64/ http://ftp.rezopole.net/centos/6.6/os/x86_64/ http://fr2.rpmfind.net/linux/centos/6.6/os/x86_64/ http://mirror.in2p3.fr/linux/CentOS/6.6/os/x86_64/ http://mirrors.ircam.fr/pub/CentOS/6.6/os/x86_64/ http://mirrors.atosworldline.com/public/centos/6.6/os/x86_64/ ~ $ curl -I -6 "http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os" HTTP/1.1 200 OK Server: nginx/1.0.15 Date: Sun, 24 May 2015 14:38:37 GMT Content-Type: text/plain Connection: keep-alive Content-Length: 0
~ $
Thanks for looking into it!
(Also, I wonder why the results don't contain centos.mirrors.ovh.net which should be closest - but that's another question for another time.)
Best regards, Felix Krohn