問題:centos 7.5安裝完之后無法連接網絡,使用yum無法正常安裝軟件,報錯could not resolve host: mirrorlist.centos.org等。(虛擬機安裝或實體主機安裝)

詳細報錯如下:

Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was
14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error"

 One of the configured repositories failed (Unknown),
 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. Disable the repository, 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 <repoid>

     4. 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=<repoid>.skip_if_unavailable=true

Cannot find a valid baseurl for repo: base/7/x86_64
這些報錯其實意思就是你的centos系統網絡不通,不相信可以使用命令 ping 114.114.114.114 測試。
解決辦法:修改網卡配置文件

進入網卡配置文件所在目錄:# cd /etc/sysconfig/network-scripts/
編輯網卡配置文件(下圖紅框中的文件):# vi ifcfg-ens33 (不用系統可能文件名不一樣)
截圖
將文件中的最后一行的ONBOOT=no 改為ONBOOT=yes,如下圖

截圖

  1. 保存文件并退出vi(按esc 然后 輸入 :wq),重啟network:# service network restart
問題解決。可以再試試Ping和yum