CentOS system Yum Source Use Error: Error:cannot retrieve repository metadata (Repomd.xml) for Repository:rpmforge.

Yum on the server was suddenly bad to use, and when Yum was used, the error was as follows:
[email protected] src]# Yum list
......
Could not retrieve mirrorlist http://mirrorlist.repoforge.org/el6/mirrors-rpmforge error was
14:pycurl ERROR 7-"couldn ' t connect to host"
Http://apt.sw.be/redhat/el6/en/x86_64/rpmforge/repodata/repomd.xml: [Errno 14]
Pycurl ERROR 7-"couldn ' t connect to host"
Trying other mirror.
Error:cannot Retrieve repository metadata (Repomd.xml) for Repository:rpmforge.
Verify its path and try again

Workaround:
Download new Centos-base.repo to/etc/yum.repos.d/
[Email protected] src]# cd/etc/yum.repos.d/
[Email protected] yum.repos.d]#

1) Download connection for centos5.*:
[Email protected] yum.repos.d]# Wget-o/etc/yum.repos.d/centos-base.repo Http://mirrors.aliyun.com/repo/Centos-5.repo

2) Download connection for centos6.*:
[Email protected] yum.repos.d]# Wget-o/etc/yum.repos.d/centos-base.repo Http://mirrors.aliyun.com/repo/Centos-6.repo

3) Download connection for centos7.*:
[Email protected] yum.repos.d]# Wget-o/etc/yum.repos.d/centos-base.repo Http://mirrors.aliyun.com/repo/Centos-7.repo

Then execute the following command:
[Email protected] yum.repos.d]# rpm-e rpmforge-release--nodeps
[email protected] yum.repos.d]# Yum Clean all
[[email protected] yum.repos.d]# Yum update

Finally, using Yum again is OK.
[email protected] yum.repos.d]# Yum list

CentOS system Yum Source Use Error: Error:cannot retrieve repository metadata (Repomd.xml) for Repository:rpmforge.