Hi Everyone: I have been fighting this all morning. I did a new (several) installs of CentOS7. Yum will not update the system. I have disabled ipv6, set yum.conf to use IPv4 only, disabled firewalld, disabled selinux, used both static ip and dhcp for network connectivity. I can ping any where on the Internet, including the mirrors, DNS works and ensured the base URL line was uncommented. Any help would be appreciated. Thanks, Ed This is the latest error I am seeing: [root at localhost ~]# yum check-update Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was 14: curl#7 - "Failed connect to mirrorlist.centos.org:80; Operation now in progress" Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=extras&infra=stock error was 14: curl#7 - "Failed connect to mirrorlist.centos.org:80; Operation now in progress" One of the configured repositories failed (Unknown), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=<repoid> ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable <repoid> or subscription-manager repos --disable=<repoid> 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true Cannot find a valid baseurl for repo: extras/7/x86_64