# Centos ネットワーク設定(網路設定)

## yum update 等 yumコマンドが走らない時の対策

## 自らをsudo ユーザにする（把自己變成sudo權限）

su -
visudo  # sudoersファイルを編集

YOUE_USER_NAME!! ALL=(ALL) NOPASSWD:ALL  #自分の名前に変えて加える


---
## 本題である（重要部分）

<details><summary>こんなエラー出てるんじゃない？？（是不是有出來這個error）</summary>

yum update  # って打ったら
    
    
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
http://ftp.jaist.ac.jp/pub/Linux/CentOS/7.7.1908/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
To address this issue please refer to the below wiki article

https://wiki.centos.org/yum-errors

If above article doesn't help to resolve this issue please use https://bugs.centos.org/.



 One of the configured repositories failed (CentOS-7 - Base),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Run the command with the repository temporarily disabled
            yum --disablerepo=base ...

     4. Disable the repository permanently, so yum won't use it by default. Yum
        will then just ignore the repository until you permanently enable it
        again or use --enablerepo for temporary usage:

            yum-config-manager --disable base
        or
            subscription-manager repos --disable=base

     5. Configure the failing repository to be skipped, if it is unavailable.
        Note that yum will try to contact the repo. when it runs most commands,
        so will have to try and fail each time (and thus. yum will be be much
        slower). If it is a very temporary problem though, this is often a nice
        compromise:

            yum-config-manager --save --setopt=base.skip_if_unavailable=true

failure: repodata/repomd.xml from base: [Errno 256] No more mirrors to try.
http://ftp.jaist.ac.jp/pub/Linux/CentOS/7.7.1908/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found

</details>
<br>

### まずはCentOSのバージョン確認しないと(確認版本)
### 私の場合は 7.7.1908

cat /etc/redhat-release  #バージョン確認コマンド

<br>

## http://ftp.jaist.ac.jp/pub/Linux/CentOS-vault/
### 🔼ここから自分のバージョンのリンクをコピー （從這個網站copy自己版本連結）

<img src="https://hackmd.io/_uploads/B1gbpASSKC.png" width="50%">

<br> <br>

sudo vi /etc/yum.repos.d/CentOS-Base.repo

# 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/?　# #で無効化する　-------------

release=$releasever&arch=$basearch&repo=os&infra=$infra

baseurl= <コピーした$URLをはる 貼$URL！！！！> os/$basearch/ #コメントアウトしてあったらはずず-

gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
enabled=1　　# これ追加 ---------------------要增加-------------------------

#released updates
[updates]
name=CentOS-$releasever - Updates

#mirrorlist=http://mirrorlist.centos.org/?　　# #で無効化する ------------

release=$releasever&arch=$basearch&repo=updates&infra=$infra
baseurl= <コピーした$URLをはる 貼$URL！！！！> updates/$basearch/ #---------------------
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
enabled=1　　# これ追加  要增加----------------------------------------------


#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras

#mirrorlist=http://mirrorlist.centos.org/?　　# #で無効化する ------------

release=$releasever&arch=$basearch&repo=extras&infra=$infra
baseurl= <コピーした$URLをはる  貼$URL！！！！> extras/$basearch/  #---------------------
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
enabled=1　　# これ追加 -----------------要增加-----------------------------

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus

#mirrorlist=http://mirrorlist.centos.org/?　　# #で無効化する ------------

release=$releasever&arch=$basearch&repo=centosplus&infra=$infra
baseurl= <コピーした$URLをはる 貼$URL！！！！> centosplus/$basearch/ #------------------
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

## これで正常に執行できます （這樣就回到正常）