NetworkManager setting resolv.conf to local IP (127.0.0.1)

joseph

So for a little over a month now I have been having to manually add DNS servers to /etc/resolv.conf whenever I log in/start up, just to access any websites. I know NetworkManager overwrites this, but if I open Networks (I imagine this is the GUI for NetworkManager on Solus), the correct DNS servers are listed under the Wired connection's settings.
Yet every few minutes, seemingly at random, NetworkManager will overwrite /etc/resolv.conf to 'nameserver 127.0.0.1'. Once this happens I am unable to resolve any websites, and solus is unable to check for updates etc.
Why is this happening, and how do I fix it?

I know it's NetworkManager editing /etc/resolv.conf as I used auditctl to set a watch on the file, just to be sure there wasn't some other process screwing things up.
I read that 'Localhost(127.0.0.1) is only used by distros/setups that run a recursive nameserver locally'. If for some reason this is what I now need to be doing, how do I run this 'recursive nameserver locally'? But more importantly, why has NetworkManager suddenly decided that this is what I want to be doing?

Am I the only one experiencing this?

Dell XPS 13 9370

ender

To my understanding, this is how it works: One shouldn't edit /etc/resovl.conf but instead set up Network Manager. The way it handles dns resolution would be (on Solus):

by default, it acquires name server from the dhcp server.
this can be changed from the GUI: right click the applet → edit connection → select connection → click gear →change ipv4/6 setting to something else than automatic(dhcp) and enter name sever IP(s)
this can be overwritten by editing the network manager configuration (/etc/NetworkManager/NetworkManager.conf or drop in file in /etc/NetworkManager/conf.d/) and setting there a dns entry (see man 5 NetworkManager.conf)

So in your case, for NM to set localhost as nameserver, it would be either that the dhcp server is enforcing it (??!), or you (or an app you installed) set your connection to use it, or you (or an app you installed) set the NM configuration to something else than default (note that this could be implicit if /etc/resolv.conf is a symlink, which is not the case by default in Solus)
If you do have a local app handling name resolution such as dnsmasq or dnscrypt-proxy (which I use and love), NM is behaving as intended and this app is the one in need of debugging.

joseph

Thanks for a detailed answer ender. I'm going to check for any programs changing my network settings, but if I don't win I'll try a clean install over the weekend.
Knowing that the default setup is still working out of the box is reassuring.
I had set up dnsmasq at some stage but I'm hazy on the details, I've since removed it from the NetworkManager confs I could find in an attempt to get back to working defaults, but to no avail.