Open up ssh client and connect to the server as root user
for 32bit: wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.i386.rpm For 64 bit http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm Install DAG’s GPG key rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt
Or/and download the rpm and install it manually:
For Centos 64:
wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.x86_64.rpm
rpm -i rpmforge-release-0.5.2-2.el5.rf.x86_64.rpm
then yum update.