The Yum Priorities plugin can be used to enforce ordered protection of repositories, by associating priorities to repositories.
The priorities plugin is a useful tool if properly configured, and used with an understanding of the functionality and a recognition of the limitations and potential issues. It can be used in conjunction with the ‘exclude’ and/or ‘includepkg’ options, as well as the ‘enabled=0′ option to disable a repo by default. This can let you choose which packages a less important repo will supersede those of a more important one.
Install Yum Priorities
# yum install yum-priorities