107

How can I disable systemd-resolved in Ubuntu 17.04?

Disabling it with systemctl disable didn't work, the service seems to be restarted (by Networkmanager?)

  • 11
    systemd-resolved isn't just big, it also breaks the way dns resolution works by not always attempting to resolve in the order dns servers are specified in the client config. When a server doesn't resolve a domain, the next in the list is moved to the top (Poettering calls that 'memory'). See this thread for the details. – LifeBoy Jun 26 '17 at 6:57
  • 7
    it also bypasses iptables rules, which is a terrible idea. – Spongman Oct 23 '18 at 3:37
189

This method works on the Ubuntu releases 17.04 (Zesty), 17.10 (Artful), 18.04 (Bionic), 18.10 (Cosmic) and 19.04 (Disco):

Disable and stop the systemd-resolved service:

sudo systemctl disable systemd-resolved
sudo systemctl stop systemd-resolved

Then put the following line in the [main] section of your /etc/NetworkManager/NetworkManager.conf:

dns=default

Delete the symlink /etc/resolv.conf

rm /etc/resolv.conf

Restart NetworkManager

sudo systemctl restart NetworkManager

Also be aware that disabling systemd-resolvd might break name resolution in VPN for some users. See this bug on launchpad (Thanks, Vincent).

| improve this answer | |
  • 4
    this does not seem to work on Ubuntu 17.04. Alsi, the config file is /etc/NetworkManager/NetworkManager.conf . Name resolving breaks when I do the above. systemd-resolved sucks big time, now the VPN DNS resolving doesn't work properly at all for me. Bug progress can be found here: bugs.launchpad.net/ubuntu/+source/systemd/+bug/1624317 – Vincent Gerris Apr 28 '17 at 10:13
  • 5
    I think you should add to the above answer that "apt-get install dnsmasq" should be done once systemd-resolved has been disabled. – LifeBoy Jun 26 '17 at 6:59
  • 8
    @LifeBoy I don't use dnsmasq. I just don't use any local nameserver, do not see the value of that. – Bastian Voigt Oct 9 '17 at 9:17
  • 11
    For Ubuntu 18.04, all that is needed is to run the commands sudo systemctl disable systemd-resolved.service and sudo service systemd-resolved stop. That worked for me. – Daniel Eagle May 5 '18 at 14:53
  • 18
    Thank you. SystemD is ruining Linux, making it from something reliable and understandable to something that works via magic. – Forbesmyester Aug 14 '18 at 8:24
22

I've recently upgraded to (k)Ubuntu 17.04 and I also stumbled upon the change to systemd.

My setup is fairly typical I think, in that I have a DNS provider in my broadband HUB and this is my primary source of information for all the devices on my network (of which I have a few).

There is some beauty in systemd, it's not all bad but what is really bad is the documentation, the lack of communication from the Ubuntu team and the gung-ho "let's just change it despite it breaks for everyone" mentality.

The solution for me after tearing some hair out was to edit /etc/systemd/resolved.conf:

[Resolve]
DNS=192.168.1.254   # <-- change to your router address
#FallbackDNS=8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844
Domains=lan         # <-- change to your localdomain name (maybe .local)
#LLMNR=yes  <-- I dabbled with this for a while but it doesn't matter
#DNSSEC=no
#Cache=yes
#DNSStubListener=udp

After not understanding why this wouldn't work I figured out that what was also needed was to switch /etc/resolv.conf to the one provided by systemd. This isn't the case in an out-of-a-box install (for reasons unknown to me).

sudo ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf

The local DNS server is then not used and all DNS requests are sent to my HUB.

I think this is a much better solution than cutting out and putting in some other solution since systemd-resolv is now the default onwards.

A related problem btw is that the /etc/nsswitch.conf is neutered.

It should read:

hosts: files mdns4_minimal dns [NOTFOUND=return] resolve [!UNAVAIL=return] dns

This is a confusing configuration since [NOTFOUND=return] means processing ends there. The entries after it will never be used.

| improve this answer | |
  • 1
    And then I have to change the router address in the config everytime I connect to a new WIFI? U serious? -1 – Bastian Voigt Jul 24 '17 at 7:25
  • I didn't realise you were roaming with it. If you are, then leave the configuration items commented out. You should then get a /etc/resolv.conf that says: nameserver 8.8.8.8 nameserver 8.8.4.4 – user2427436 Jul 25 '17 at 18:58
  • 1
    I don't think it's necessary to edit resolved.conf if you set up netplan correctly. i.e., netplan writes the correct values to the symlinked file... PS SYSTEMD SUCKS! – g33kz0r Jan 7 '19 at 11:56
  • I prefer taking all the resolver-breakers out. there's usually not more than 2-3 legit resolver updates in 5 years of lifetime of 10000s of servers but guys keep optimizing for a laptop. doesn't matter to them if companies lose millions due to prolonged outages caused by this stuff, and the impact on safety-critical systems is just waved away by "those people will test/optimize it anyway". yup. by removing it. so noone dies. – Florian Heigl Apr 11 at 16:38
7

If you are using Ubuntu 18.04 Server, none of these answers apply. The one by user2427436 comes closest.

The issue is that systemd-resolved is/runs a stub resolver, and I just need to completely disable that (per the question). I need to do this because Zimbra 8.8.15 (FOSS) comes with its own integrated resolver (unbound).

In my situation I am starting from a stock (naive) install of server 18.04, with minimal options on bare metal (well, actually a VM).

so here's the recipe:

   vi /etc/systemd/resolved.conf
     edit line #DNSStubListener=yes
         to be DNSStubListener=no
   systemctl stop systemd-resolved
   systemctl status systemd-resolved
   rm /etc/resolv.conf
   reboot to test...

This is what /etc/systemd/resolved.conf looks like now:

# See resolved.conf(5) for details
[Resolve]
#DNS=
#FallbackDNS=
#Domains=
#LLMNR=no
#MulticastDNS=no
#DNSSEC=no
#Cache=yes
#DNSStubListener=yes
DNSStubListener=no

that's all it took.

Feel free to install any other resolver you want after this.

| improve this answer | |
3

If you are having leaks issues with your VPN and can't figure out how to set up systemd (like me) you can remove it in the way described in the first answer but don't add the dns=default line because it will activate the nameserver 127.0.0.1. To set the router as dns, create the file "tail" in your /etc/resolvconf/resolv.conf.d/ folder adding the line nameserser 192.168.1.1

do ln -sf /var/run/resolved/resolv.conf /etc/resolv.confif you had messed up with this file.

| improve this answer | |
  • 1
    Really? For me it works exactly as described in my answer. Definitly not using nameserver 127.0.0.1. I also think it is not very handy to hardcode the IP of your nameserver in a config file. At least I switch wifi networks quite often and each wifi has a different nameserver – Bastian Voigt Sep 6 '17 at 14:42
  • yes 'default' enables 127.0.0.1 as dns – Yvain Sep 8 '17 at 17:33

Not the answer you're looking for? Browse other questions tagged or ask your own question.