Solution: I just had to create the file
I wanted to install Pi-Hole on my server and noticed that port 53 is already in use by something.
Apparently it is in use by systemd-resolved:
~$ sudo lsof -i -P -n | grep LISTEN
[...]
systemd-r 799 systemd-resolve 18u IPv4 7018 0t0 TCP 127.0.0.53:53 (LISTEN)
systemd-r 799 systemd-resolve 20u IPv4 7020 0t0 TCP 127.0.0.54:53 (LISTEN)
[...]
And the solution should be to edit /etc/systemd/resolved.conf by changing DNSStubListener=yes to DNSStubListener=no according to this post I found. But the /etc/systemd/resolved.conf doesn’t exist on my server.
I’ve tried sudo dnf install /etc/systemd/resolved.conf which did nothing other than telling me that systemd-resolved is already installed of course. Rebooting also didn’t work. I don’t know what else I could try.
I’m running Fedora Server.
Is there another way to stop systemd-resolved from listening on port 53? If not how do I fix my missing .conf file?
The service is using the default config, which you can override by creating this file.
View the package contents to find out where the default config is located.
Yep, it might be enough to just add that file with the setting set to no and restart.
Here is a good primer on the configuration files and their possible locations: https://www.freedesktop.org/software/systemd/man/latest/resolved.conf.html
Edit: be careful because this is your domain name lookup you’re messing with. 😊
The domain name shouldn’t matter
FWIW, I’m referring to the local DNS (domain name system) resolver; the mechanism that resolves local domain names into IP addresses so that computers can talk to each other over the LAN.
I know
It still won’t really matter. The domain name is arbitrary in this case
Disable systemd-resolved.service? Uninstall systemd-resolved?
Um, dnf doesn’t do anything with configuration files. It is used for packages.
I would start by trying to create that file. If that doesn’t fix it after restarting the service look into the docs. You may need to configure network manager.
It tries to install the associated package when given a path to a configuration file.
They probably moved it to somewhere under /usr or /var/lib.
When I installed it it suggested turning that service off onvthe host. If you search online there are many suggestions on shutting off that stuff so 53 is left for pihole
As a temporary fix, instead of service systemd-resolved restart as per the article, you can try this, service systemd-resolved stop
Once the service is stopped the port should be free. You’ll have to do this on every reboot (though maybe you can try adding the command to /etc/rc.local to stop it on every reboot)
