Old Configuration Method
I used to configure it by hand, and this information can be useful at times as well:
Install the Dag repository
rpm --import http://dag.wieers.com/packages/RPM-GPG-KEY.dag.txt cat <<EOF > /etc/yum.repos.d/dag.repo [dag] name=Dag RPM Repository for Red Hat Enterprise Linux baseurl=http://apt.sw.be/redhat/el\$releasever/en/\$basearch/dag gpgcheck=1 enabled=1 EOF
From time to time of late Dag's main mirror is broken here is an alternate config posted to the Centos mailing list by Phil Schaffner
Install the Dag repository with mirrors
rpm --import http://dag.wieers.com/packages/RPM-GPG-KEY.dag.txt
cat <<EOF > /etc/yum.repos.d/dag.repo
[dag]
name=Dag RPM Repository for Red Hat Enterprise Linux
baseurl=http://dag.atrpms.net/redhat/el\$releasever/en/\$basearch/dag/
http://dag.freshrpms.net/redhat/el\$releasever/en/\$basearch/dag/
http://ftp.heanet.ie/pub/freshrpms/pub/dag/redhat/el\$releasever/en/\$basearch/dag/
http://apt.sw.be/redhat/el\$releasever/en/\$basearch/dag/
failovermethod=priority
enabled=1
gpgcheck=1
EOF