[Errno 4]IOError: urlopen error (97, ‚Address family not supported by protocol’)

Yum Configuration

Issue:
[root@root]# yum update
Loaded plugins: fastestmirror, security
Determining fastest mirrors
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=5&arch=x86_64&repo=os error was
[Errno 4] IOError:
Error: Cannot find a valid baseurl for repo: base
[root@root]#

If you have above problem, enable proxy in yum.conf file.

Solution:

Update the yum configuration file.

eg: 10.0.0.1:8080

[root@root]# cd /etc/yum/
[root@root]# vi yum.conf
Add following lines
[main]
proxy=http://10.0.0.1:8080
[root@root]#

where 10.0.0.1 is your Proxy Server.