systemd-resolved and resolvctl on ubuntu; 127.0.0.53 nameserver;

前段时间，我偶然进行查看linux DNS配置，通过查看 /etc/resolv.conf 文件，得到如下结果：

?  devices ll /etc/resolv.conf
lrwxrwxrwx 1 root root 39 12月 28 18:55 /etc/resolv.conf -> ../run/systemd/resolve/stub-resolv.conf
?  devices cat /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.conf(5) in a different way,
# replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.

nameserver 127.0.0.53
options edns0 trust-ad

我之前，曾经简单写过一个linux 下，如何获取dns服务器的博客：；但是无论怎么查找，显示的都是 127.0.0.53 回环地址。说明ubuntu内核对dns服务器做了一层代理；但是我内部的机制不是很明白。所以今天进行简要了解一下，填一下年前遗留的一个坑。