Here is the content for a new repo file that need to be installed in a linux server:
 
Name the repo file ” CentOS-Base.repo ” in the location
/etc/yum.repos.d/
 
# CentOS-Base.repo
#
# This file uses a new mirrorlist system developed by Lance Davis for CentOS.
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client.  You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#

[base]
name=CentOS-$releasever – Base
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
baseurl=http://vault.centos.org/4.9/os/$basearch/
gpgcheck=1
gpgkey=http://vault.centos.org/4.9RPM-GPG-KEY-centos4

#released updates
[update]
name=CentOS-$releasever – Updates
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
baseurl=http://vault.centos.org/4.9/updates/$basearch/
#baseurl=http://vault.centos.org/4.9$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://vault.centos.org/4.9RPM-GPG-KEY-centos4

#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever – Addons
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=addons
baseurl=http://vault.centos.org/4.9/addons/$basearch/
gpgcheck=1
gpgkey=http://vault.centos.org/4.9RPM-GPG-KEY-centos4

#additional packages that may be useful
[extras]
name=CentOS-$releasever – Extras
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
baseurl=http://vault.centos.org/4.9/extras/$basearch/
gpgcheck=1
gpgkey=http://vault.centos.org/4.9RPM-GPG-KEY-centos4

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever – Plus
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
baseurl=http://vault.centos.org/4.9/centosplus/$basearch/
gpgcheck=1
enabled=1
gpgkey=http://vault.centos.org/4.9RPM-GPG-KEY-centos4

#contrib – packages by Centos Users
[contrib]
name=CentOS-$releasever – Contrib
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
baseurl=http://vault.centos.org/4.9/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://vault.centos.org/4.9RPM-GPG-KEY-centos4