Rpmforge 网站：http://repoforge.org/

1、下载软件源RPM安装包
到http://repoforge.org/use/下载对应系统版本的RPM包，如：

wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.i686.rpm

2、安装DAG的PGP Key
到CentOS Wiki查看对应系统PGP KEY的命令，如：

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

3、验证刚才下载的Rpmforge的rpm文件包，如

rpm -K rpmforge-release-0.5.2-2.el6.rf.i686.rpm

4、安装Rpmforge的rpm文件包

rpm -i rpmforge-release-0.5.2-2.el6.rf.i686.rpm

5、设置rpmforge.repo权限
打开/etc/rpmforge.repo，添加priority=12（数值推荐大于10，需要安装yum-priorities插件），如：

### Name: RPMforge RPM Repository for RHEL 6 - dag
### URL: http://rpmforge.net/
[rpmforge]
name = RHEL $releasever - RPMforge.net - dag
baseurl = http://apt.sw.be/redhat/el6/en/$basearch/rpmforge
mirrorlist = http://apt.sw.be/redhat/el6/en/mirrors-rpmforge
#mirrorlist = file:///etc/yum.repos.d/mirrors-rpmforge
enabled = 1
protect = 0
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag
gpgcheck = 1
priority=12

PS：我比较懒，没有装这个插件，所以也没设置这个……