在安装软件telnet时出现出如下错误：
# yum install -y telnet
Failed to set locale, defaulting to C
Loaded plugins: fastestmirror, security
Setting up Install Process
Loading mirror speeds from cached hostfile
* base: ftp.sjtu.edu.cn
* extras: ftp.sjtu.edu.cn
* updates: ftp.sjtu.edu.cn
http://ftp.sjtu.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
To address this issue please refer to the below knowledge base article
https://access.redhat.com/articles/1320623
If above article doesn't help to resolve this issue please open a ticket with Red Hat Support.
http://mirror.bit.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.aliyun.com/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.cqu.edu.cn/CentOS/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.huaweicloud.com/repository/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.neusoft.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.njupt.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.nwsuaf.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
^C
Current download cancelled, interrupt (ctrl-c) again within two seconds
to exit.
http://mirrors.zju.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://ftp.sjtu.edu.cn/centos/6.9/extras/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirror.bit.edu.cn/centos/6.9/extras/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirror.lzu.edu.cn/centos/6.9/extras/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.aliyun.com/centos/6.9/extras/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.cn99.com/centos/6.9/extras/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.huaweicloud.com/repository/centos/6.9/extras/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.nju.edu.cn/centos/6.9/extras/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.shu.edu.cn/centos/6.9/extras/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.tuna.tsinghua.edu.cn/centos/6.9/extras/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.zju.edu.cn/centos/6.9/extras/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://ftp.sjtu.edu.cn/centos/6.9/updates/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirror.lzu.edu.cn/centos/6.9/updates/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.163.com/centos/6.9/updates/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.cn99.com/centos/6.9/updates/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.huaweicloud.com/repository/centos/6.9/updates/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.neusoft.edu.cn/centos/6.9/updates/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.nwsuaf.edu.cn/centos/6.9/updates/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.sohu.com/centos/6.9/updates/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 7 - "couldn't connect to host"
Trying other mirror.
http://mirrors.tuna.tsinghua.edu.cn/centos/6.9/updates/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.zju.edu.cn/centos/6.9/updates/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
Resolving Dependencies
--> Running transaction check
---> Package telnet.x86_64 1:0.17-48.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=================================================================================================================================
Package Arch Version Repository Size
=================================================================================================================================
Installing:
telnet x86_64 1:0.17-48.el6 base 58 k
Transaction Summary
=================================================================================================================================
Install 1 Package(s)
Total download size: 58 k
Installed size: 109 k
Downloading Packages:
http://ftp.sjtu.edu.cn/centos/6.9/os/x86_64/Packages/telnet-0.17-48.el6.x86_64.rpm: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirror.bit.edu.cn/centos/6.9/os/x86_64/Packages/telnet-0.17-48.el6.x86_64.rpm: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.aliyun.com/centos/6.9/os/x86_64/Packages/telnet-0.17-48.el6.x86_64.rpm: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.cqu.edu.cn/CentOS/6.9/os/x86_64/Packages/telnet-0.17-48.el6.x86_64.rpm: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.huaweicloud.com/repository/centos/6.9/os/x86_64/Packages/telnet-0.17-48.el6.x86_64.rpm: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.neusoft.edu.cn/centos/6.9/os/x86_64/Packages/telnet-0.17-48.el6.x86_64.rpm: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.njupt.edu.cn/centos/6.9/os/x86_64/Packages/telnet-0.17-48.el6.x86_64.rpm: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.nwsuaf.edu.cn/centos/6.9/os/x86_64/Packages/telnet-0.17-48.el6.x86_64.rpm: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.sohu.com/centos/6.9/os/x86_64/Packages/telnet-0.17-48.el6.x86_64.rpm: [Errno 14] PYCURL ERROR 7 - "couldn't connect to host"
Trying other mirror.
http://mirrors.zju.edu.cn/centos/6.9/os/x86_64/Packages/telnet-0.17-48.el6.x86_64.rpm: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
Error Downloading Packages:
1:telnet-0.17-48.el6.x86_64: failure: Packages/telnet-0.17-48.el6.x86_64.rpm from base: [Errno 256] No more mirrors to try.
[root@nfs01 yum.repos.d]# yum makecache
Failed to set locale, defaulting to C
Loaded plugins: fastestmirror, security
Loading mirror speeds from cached hostfile
* base: ftp.sjtu.edu.cn
* extras: ftp.sjtu.edu.cn
* updates: ftp.sjtu.edu.cn
http://ftp.sjtu.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
To address this issue please refer to the below knowledge base article
https://access.redhat.com/articles/1320623
If above article doesn't help to resolve this issue please open a ticket with Red Hat Support.
http://mirror.bit.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.aliyun.com/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.cqu.edu.cn/CentOS/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.huaweicloud.com/repository/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.neusoft.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.njupt.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.nwsuaf.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.sohu.com/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 7 - "couldn't connect to host"
Trying other mirror.
http://mirrors.zju.edu.cn/centos/6.9/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://ftp.sjtu.edu.cn/centos/6.9/os/x86_64/repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirror.bit.edu.cn/centos/6.9/os/x86_64/repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.aliyun.com/centos/6.9/os/x86_64/repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.cqu.edu.cn/CentOS/6.9/os/x86_64/repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.huaweicloud.com/repository/centos/6.9/os/x86_64/repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.neusoft.edu.cn/centos/6.9/os/x86_64/repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.njupt.edu.cn/centos/6.9/os/x86_64/repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.nwsuaf.edu.cn/centos/6.9/os/x86_64/repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.sohu.com/centos/6.9/os/x86_64/repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 7 - "couldn't connect to host"
Trying other mirror.
http://mirrors.zju.edu.cn/centos/6.9/os/x86_64/repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
Error: failure: repodata/57de5f5b01f94e309bc9d2cd5bc0d638826ae37477cb14b3517e32323e8a72ab-filelists.sqlite.bz2 from base: [Errno 256] No more mirrors to try.
但是测试外网时，我的网络又是正常的，如下：
经过在51cto上面查看，才发现是Yum源损坏，按照如下进行下载并替换：
先把原本的yum源重命名进行保存
然后到http://mirrors.163.com/.help/centos.html下载自己需要的版本，我这里是centos6,
然后通过命令rz把文件上传到linux目录下，
再进行安装测试：
至此，这个问题就解决了，在这里要感谢@deadkev，看了他的博文，才有所感想，才成功，再次感谢；
备注：我这里使用的是客户端是：secureCRT，如若有问题，请联系，感谢。