报错背景
CentOS 系统无法识别 ifconfig 命令
报错
解决办法
起初想通过安装 net-tools 来解决，但是无法从默认镜像仓库中下载
无法下载 net-tools
从网络查阅资料：如果网络正常，问题可能是当前的镜像源出现故障或者当前网络无法访问镜像源。可以尝试更换为其他可用的镜像源。
可以通过 vi 命令编辑 /etc/yum.repos.d/CentOS-Base.repo 文件，将其中的 mirrorlist 行用 # 号注释掉，并将 baseurl 行取消注释，并修改为其他可靠的镜像地址。
vi /etc/yum.repos.d/CentOS-Base.repo
更新内容如下：
# 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-$releasever - Base
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
下载测试
测试 yum install net-tools 安装命令
[root@localhost ~]# yum install net-tools
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
base | 3.6 kB 00:00:00
extras | 2.9 kB 00:00:00
updates | 2.9 kB 00:00:00
(1/4): base/7/x86_64/group_gz | 153 kB 00:00:00
(2/4): extras/7/x86_64/primary_db | 253 kB 00:00:00
(3/4): base/7/x86_64/primary_db | 6.1 MB 00:00:00
(4/4): updates/7/x86_64/primary_db | 27 MB 00:00:01
Resolving Dependencies
--> Running transaction check
---> Package net-tools.x86_64 0:2.0-0.25.20131004git.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==============================================================================================================================================================
Package Arch Version Repository Size
==============================================================================================================================================================
Installing:
net-tools x86_64 2.0-0.25.20131004git.el7 base 306 k
Transaction Summary
==============================================================================================================================================================
Install 1 Package
Total download size: 306 k
Installed size: 917 k
Is this ok [y/d/N]: y
Downloading packages:
warning: /var/cache/yum/x86_64/7/base/packages/net-tools-2.0-0.25.20131004git.el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY
Public key for net-tools-2.0-0.25.20131004git.el7.x86_64.rpm is not installed
net-tools-2.0-0.25.20131004git.el7.x86_64.rpm | 306 kB 00:00:00
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Importing GPG key 0xF4A80EB5:
Userid : "CentOS-7 Key (CentOS 7 Official Signing Key) <security@centos.org>"
Fingerprint: 6341 ab27 53d7 8a78 a7c2 7bb1 24c6 a8a7 f4a8 0eb5
Package : centos-release-7-8.2003.0.el7.centos.x86_64 (@anaconda)
From : /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Is this ok [y/N]: y
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : net-tools-2.0-0.25.20131004git.el7.x86_64 1/1
Verifying : net-tools-2.0-0.25.20131004git.el7.x86_64 1/1
Installed:
net-tools.x86_64 0:2.0-0.25.20131004git.el7
Complete!
[root@localhost ~]#
再次执行 ifconfig，成功
成功
