yum下载软件包时报错

yum 下载文件时报错：
You can remove cached packages by executing ‘dnf clean packages’.
错误：下载软件包错误：
Curl error (6): Couldn’t resolve host name for https://mirrors.fedoraproject.org/metalink?repo=updates-released-f23&arch=x86_64 [Could not resolve host: mirrors.fedoraproject.org]

原因：
DNS服务器错误

解决：
修改/etc/resolv.conf文件，添加一个nameserver 8.8.8.8