Linux系统DNS设置
之前在文件
/etc/resolv.conf中设置了，过段时间总是自动恢复默认值。（注释中写的很详细，是不可编辑的由系统自动生成的文件）
/etc/resolv.conf # This file is managed by man:systemd-resolved(8). Do not edit. # # This is a dynamic resolv.conf file for connecting local clients to the # internal DNS stub resolver of systemd-resolved. This file lists all # configured search domains. # # Run "resolvectl status" to see details about the uplink DNS servers # currently in use. # # Third party programs must not access this file directly, but only through the # symlink at /etc/resolv.conf. To manage man:resolv.