[Errno 14] PYCURL ERROR 7 – “Couldn’t connect to host” solution
The new server points to the original server’s yum source, and after the configuration is completed, the
yum clean all operation and yum repolist
error are reported

[root@hadoop101 yum.repos.d]# yum repolist
Plugins loaded: fastestmirror, refresh-packagekit, security
Determining fastest mirrors
 * extras: mirror.bit.edu.cn
 * updates: ap.stykers.moe
http://192.168.1.100/cdrom/repodata/repomd.xml: [Errno 14] PYCURL ERROR 7 - "couldn't connect to host"
Try other mirrors.
http://192.168.1.100/cdrom/repodata/repomd.xml: [Errno 14] PYCURL ERROR 7 - "couldn't connect to host"
Try other mirrors.
extras                                                                    | 3.4 kB     00:00     
extras/primary_db                                                         |  29 kB     00:00     
updates                                                                   | 3.4 kB     00:00     
updates/primary_db                                                        | 3.7 MB     00:02 

The problem is a firewall problem
solution: return to the primary server
type /etc/init.d/iptables stop
or chkconfig iptables off
to close the firewall