Hi, Disabled ipv6 (using sysctl, disabled ip6tables, no reboot, no proxy present) and still get the message as below. Centos 6.3 (i know its old) Kernel : 2.6.32-279.14.1.el6.x86_64 (I know its old) Standard /etc/yum.conf (no changes) Standard repos (centos base), enabled Cleaned cache: yum metadata (didn't work) Then: yum clean all (didn't work) Then yum makecache (didn't work) Yum repolist Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os error was 14: PYCURL ERROR 7 - "Failed to connect to 2a02:2498:1:3d:5054:ff:fed3:e91a: Network is unreachable" Ping on mirrorlist.centos.org is OK Curl mirrrorlist.centos.org NOT_OK Message started to occur suddenly, I didn't even update any package. Any suggestions ?