[Dnsmasq-discuss] Avoid conflicts between dnsmasq and systemd-resolved.

[Hongyi Zhao]

Hi,

On Ubuntu 20.04, I let dnsmasq listen on 127.0.0.1:53, at the same
time, I also noted that systemd-resolved has a default stub dns
resolver which is listening on 127.0.0.53:53.

And for my case, the /etc/resolv.conf is a symlink as following:

$ realpath -e /etc/resolv.conf
/run/systemd/resolve/stub-resolv.conf

The content of this file is shown as follows:

$ 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


I use the netplan to set 127.0.0.1 as the dns for all interfaces. But
it seems there are some conflicts on my above configuration. Say, when
I do the following testing:

$ dig www.baidu.com

I always noticed that there will have multiple dnsmasq instances be
triggered automatically and the resolution will fail.

So I want to know how to solve the confliction problem between dnsmasq
and systemd-resolved.

Regards,
-- 
Hongyi Zhao <hongyi.zhao at gmail.com>