CentOS

I have a centos 6.8 box and now want to upgrade to 7.x (whichever the newest version is).

Hoever, when I run the command yum update (as root) I get this:
PYCURL ERROR 6 - "Couldn't resolve host 'mirrorlist.centos.org'"
Error: Cannot find a valid baseurl for repo: centosplus

Any suggestions how to fix this?

Thanks

You cannot upgrade from 6.x to 7.x. You have to reinstall.