Enable RPMForge Repository on CentOS 6

1. Import the key of the RPMForge repository:

   sudo rpm --import http://apt.sw.be/RPM-GPG-KEY.dag.txt

2. Download the repository RPM:

   wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el6.rf.$(uname -m).rpm

3. Verify the downloaded RPM package:

   rpm -K rpmforge-release-0.5.3-1.el6.rf.$(uname -m).rpm

4. Install the RPM package:

   sudo rpm -i rpmforge-release-0.5.3-1.el6.rf.$(uname -m).rpm