How to avoid conflicts between dnsmasq and systemd-resolved?
As of systemd 232 (released in 2017) you can edit /etc/systemd/resolved.conf and add this line:
DNSStubListener=no
This will switch off binding to port 53.
The option is described in more details in the resolved.conf manpage.
You can find the systemd version your system is running with:
systemctl --version
You can disable systemd-resolved from loading at boot using sudo systemctl disable systemd-resolved.
If you want to run the two together, you can redirect the systemd-resolved to use the localhost as the primary nameserver. This will make sure that all queries are directed to dnsmasq for resolution before hitting the external DNS server. This can be done by adding the line nameserver 127.0.0.1 at the top of your /etc/resolv.conf file. This will also disable systemd's local caching.
You can read more on the Arch Linux wiki. I copied this from there and it covers it quite well.
However this does not reliably avoid the error at boot time, i.e. dnsmasq will still fail if systemd-resolved happens to start first. If your version of systemd is new enough, use the answer by Malvineous. If your version of systemd is too old, you can work around this problem by modifying the dnsmasq unit: in the [Unit] section, add Before=systemd-resolved .
After this, if you like, you can create a separate /etc/dnsmasq-resolv.conf file for the upstream nameservers and pass it using the -r or --resolv-file option, or add the upstream nameservers to the dnsmasq configuration file and use the -R or --no-resolv option. This way you only have the localhost in your /etc/resolv.conf and everything goes through dnsmasq.
I just enabled option "bind-interfaces" by removing '#' at the start of the line in /etc/dnsmasq.conf.
I was able to start dnsmasq again:
- dnsmasq bind DNS port on all interfaces (including 127.0.0.1) port 53,
- systemd-resolv keeps listening on 127.0.0.53:53
I was pointed to this solution by this discussion resolved: add an option to disable the stub resolver