centos使用网易yum源提示404错误解决办法

本地安装的centos5.5，使用网易163 yum更新源的时候，提示404错误：[Errno 14] HTTP Error 404: Not Found

直接相应的地址，发现网易镜像网站目录里已经不存在此页，真正存储这些文件的地址是http://mirrors.163.com/centos/5/

于是根据情况修改CentOS5-Base-163如下：

# CentOS-Base.repo
#
# 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-5 - Base - 163.com
baseurl=http://mirrors.163.com/centos/5/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=5&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

#released updates 
[updates]
name=CentOS-5 - Updates - 163.com
baseurl=http://mirrors.163.com/centos/5/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=5&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

#packages used/produced in the build but not released
[addons]
name=CentOS-5 - Addons - 163.com
baseurl=http://mirrors.163.com/centos/5/addons/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=5&arch=$basearch&repo=addons
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

#additional packages that may be useful
[extras]
name=CentOS-5 - Extras - 163.com
baseurl=http://mirrors.163.com/centos/5/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=5&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-5 - Plus - 163.com
baseurl=http://mirrors.163.com/centos/5/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=5&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

#contrib - packages by Centos Users
[contrib]
name=CentOS-5 - Contrib - 163.com
baseurl=http://mirrors.163.com/centos/5/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=5&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5