systemd-resolved not starting on boot

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You installed something like resolvconf which cuts sytemd-resolved off entirely by commenting out the 53 listening address in stub-resolv.conf which the /etc/resolv.conf should link to.For a fresh Ubuntu 18.04 install, the only additional name resolution package I needed was libnss-resolve. I never use resolvconf, so don't know why you need it.

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Paul Schreiber
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Paul Schreiber

Updated on September 18, 2022

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  • Paul Schreiber
    Paul Schreiber over 1 year

    When I boot my Ubuntu server, DNS resolving does not work. You can most easily see this by looking at resolv.conf:

    ~ # cat /etc/resolv.conf 
    # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
    #     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
    # 127.0.0.53 is the systemd-resolved stub resolver.
    # run "systemd-resolve --status" to see details about the actual nameservers.
    

    I then enable the resolved service:

    ~ # systemctl enable systemd-resolved.service
    

    And things work as expected:

    ~ # cat /etc/resolv.conf 
    # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
    #     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
    # 127.0.0.53 is the systemd-resolved stub resolver.
    # run "systemd-resolve --status" to see details about the actual nameservers.
    
    nameserver 127.0.0.53
    

    Config

    • Ubuntu 19.04
    • 5.0.0-23-generic

    Related packages installed:

    ~ # cat /etc/resodpkg -l |grep systemd
    ii  libnss-resolve:amd64                  240-6ubuntu5.2                        amd64        nss module to resolve names via systemd-resolved
    ii  libnss-systemd:amd64                  240-6ubuntu5.2                        amd64        nss module providing dynamic user and group name resolution
    ii  libpam-systemd:amd64                  240-6ubuntu5.2                        amd64        system and service manager - PAM module
    ii  libsystemd0:amd64                     240-6ubuntu5.2                        amd64        systemd utility library
    ii  networkd-dispatcher                   2.0-2                                 all          Dispatcher service for systemd-networkd connection status changes
    ii  python3-systemd                       234-2build2                           amd64        Python 3 bindings for systemd
    ii  systemd                               240-6ubuntu5.2                        amd64        system and service manager
    ii  systemd-sysv                          240-6ubuntu5.2                        amd64        system and service manager - SysV links
    ~ # dpkg -l |grepdpkg -l |grep resolv
    ii  libc-ares2:amd64                      1.14.0-1                              amd64        asynchronous name resolver
    ii  libgeoip1:amd64                       1.6.12-1                              amd64        non-DNS IP-to-country resolver library
    ii  libnss-resolve:amd64                  240-6ubuntu5.2                        amd64        nss module to resolve names via systemd-resolved
    ii  resolvconf                            1.79ubuntu13                          all          name server information handler
    

    Name resolution worked on boot prior to updating to 19.04.

    No apparent errors in syslog. Related excerpt:

    Aug  3 11:41:16 green systemd[1]: Starting Network Name Resolution...
    Aug  3 11:41:16 green systemd-resolved[807]: Positive Trust Anchors:
    Aug  3 11:41:16 green systemd-resolved[807]: . IN DS 19036 8 2 49aac11d7b6f6446702e54a1607371607a1a41855200fd2ce1cdde32f24e8fb5
    Aug  3 11:41:16 green systemd-resolved[807]: . IN DS 20326 8 2 e06d44b80b8f1d39a95c0b0d7c65d08458e880409bbc683457104237c7f8ec8d
    Aug  3 11:41:16 green systemd-resolved[807]: Negative trust anchors: 10.in-addr.arpa 16.172.in-addr.arpa 17.172.in-addr.arpa 18.172.in-addr.arpa 19.172.in-addr.arpa 20.172.in-addr.arpa 21.172.in-addr.arp
    Aug  3 11:41:16 green systemd[1]: Started Network Name Resolution.
    

    Status before reboot (with nameserver listed in /etc/resolv.conf):

    ~ # systemctl status systemd-resolved.service
    ● systemd-resolved.service - Network Name Resolution
       Loaded: loaded (/lib/systemd/system/systemd-resolved.service; enabled; vendor preset: enabled)
       Active: active (running) since Sat 2019-08-03 11:39:32 EDT; 2 days ago
         Docs: man:systemd-resolved.service(8)
               https://www.freedesktop.org/wiki/Software/systemd/resolved
               https://www.freedesktop.org/wiki/Software/systemd/writing-network-configuration-managers
               https://www.freedesktop.org/wiki/Software/systemd/writing-resolver-clients
     Main PID: 807 (systemd-resolve)
       Status: "Processing requests..."
        Tasks: 1 (limit: 4915)
       Memory: 7.9M
       CGroup: /system.slice/systemd-resolved.service
               └─807 /lib/systemd/systemd-resolved
    
    Aug 06 10:00:38 green systemd-resolved[807]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:04:06 green systemd-resolved[807]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:04:06 green systemd-resolved[807]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:04:06 green systemd-resolved[807]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:04:06 green systemd-resolved[807]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:15:53 green systemd-resolved[807]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:17:05 green systemd-resolved[807]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:17:05 green systemd-resolved[807]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:17:05 green systemd-resolved[807]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:17:05 green systemd-resolved[807]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    

    Status before reboot (with nothing listed in /etc/resolv.conf):

    ~ # systemctl status systemd-resolved.service
    ● systemd-resolved.service - Network Name Resolution
       Loaded: loaded (/lib/systemd/system/systemd-resolved.service; enabled; vendor preset: enabled)
       Active: active (running) since Tue 2019-08-06 10:23:53 EDT; 1min 9s ago
         Docs: man:systemd-resolved.service(8)
               https://www.freedesktop.org/wiki/Software/systemd/resolved
               https://www.freedesktop.org/wiki/Software/systemd/writing-network-configuration-managers
               https://www.freedesktop.org/wiki/Software/systemd/writing-resolver-clients
     Main PID: 798 (systemd-resolve)
       Status: "Processing requests..."
        Tasks: 1 (limit: 4915)
       Memory: 7.8M
       CGroup: /system.slice/systemd-resolved.service
               └─798 /lib/systemd/systemd-resolved
    
    Aug 06 10:23:51 green systemd[1]: Starting Network Name Resolution...
    Aug 06 10:23:52 green systemd-resolved[798]: Positive Trust Anchors:
    Aug 06 10:23:52 green systemd-resolved[798]: . IN DS 19036 8 2 49aac11d7b6f6446702e54a1607371607a1a41855200fd2ce1cdde32f24e8fb5
    Aug 06 10:23:52 green systemd-resolved[798]: . IN DS 20326 8 2 e06d44b80b8f1d39a95c0b0d7c65d08458e880409bbc683457104237c7f8ec8d
    Aug 06 10:23:52 green systemd-resolved[798]: Negative trust anchors: 10.in-addr.arpa 16.172.in-addr.arpa 17.172.in-addr.arpa 18.172.in-addr.arpa 19.172.in-addr.arpa 20.
    Aug 06 10:23:52 green systemd-resolved[798]: Using system hostname 'green'.
    Aug 06 10:23:53 green systemd[1]: Started Network Name Resolution.
    
    ~ # systemd-resolve --status
    Global
           LLMNR setting: no
    MulticastDNS setting: no
      DNSOverTLS setting: no
          DNSSEC setting: no
        DNSSEC supported: no
      Current DNS Server: 8.8.8.8
             DNS Servers: 8.8.8.8
                          8.8.4.4
              DNSSEC NTA: 10.in-addr.arpa
                          16.172.in-addr.arpa
                          168.192.in-addr.arpa
                          17.172.in-addr.arpa
                          18.172.in-addr.arpa
                          19.172.in-addr.arpa
                          20.172.in-addr.arpa
                          21.172.in-addr.arpa
                          22.172.in-addr.arpa
                          23.172.in-addr.arpa
                          24.172.in-addr.arpa
                          25.172.in-addr.arpa
                          26.172.in-addr.arpa
                          27.172.in-addr.arpa
                          28.172.in-addr.arpa
                          29.172.in-addr.arpa
                          30.172.in-addr.arpa
                          31.172.in-addr.arpa
                          corp
                          d.f.ip6.arpa
                          home
                          internal
                          intranet
                          lan
                          local
                          private
                          test
    
    Link 3 (eno2)
          Current Scopes: none
    DefaultRoute setting: no
           LLMNR setting: yes
    MulticastDNS setting: no
      DNSOverTLS setting: no
          DNSSEC setting: no
        DNSSEC supported: no
    
    Link 2 (eno1)
          Current Scopes: none
    DefaultRoute setting: no
           LLMNR setting: yes
    MulticastDNS setting: no
      DNSOverTLS setting: no
          DNSSEC setting: no
        DNSSEC supported: no
    

    After systemctl enable systemd-resolved.service(with nameserver listed in /etc/resolv.conf):

    ~ # systemctl status systemd-resolved.service
    ● systemd-resolved.service - Network Name Resolution
       Loaded: loaded (/lib/systemd/system/systemd-resolved.service; enabled; vendor preset: enabled)
       Active: active (running) since Tue 2019-08-06 10:23:53 EDT; 3min 47s ago
         Docs: man:systemd-resolved.service(8)
               https://www.freedesktop.org/wiki/Software/systemd/resolved
               https://www.freedesktop.org/wiki/Software/systemd/writing-network-configuration-managers
               https://www.freedesktop.org/wiki/Software/systemd/writing-resolver-clients
     Main PID: 798 (systemd-resolve)
       Status: "Processing requests..."
        Tasks: 1 (limit: 4915)
       Memory: 7.9M
       CGroup: /system.slice/systemd-resolved.service
               └─798 /lib/systemd/systemd-resolved
    
    Aug 06 10:23:52 green systemd-resolved[798]: Positive Trust Anchors:
    Aug 06 10:23:52 green systemd-resolved[798]: . IN DS 19036 8 2 49aac11d7b6f6446702e54a1607371607a1a41855200fd2ce1cdde32f24e8fb5
    Aug 06 10:23:52 green systemd-resolved[798]: . IN DS 20326 8 2 e06d44b80b8f1d39a95c0b0d7c65d08458e880409bbc683457104237c7f8ec8d
    Aug 06 10:23:52 green systemd-resolved[798]: Negative trust anchors: 10.in-addr.arpa 16.172.in-addr.arpa 17.172.in-addr.arpa 18.172.in-addr.arpa 19.172.in-addr.arpa 20.
    Aug 06 10:23:52 green systemd-resolved[798]: Using system hostname 'green'.
    Aug 06 10:23:53 green systemd[1]: Started Network Name Resolution.
    Aug 06 10:27:32 green systemd-resolved[798]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:27:35 green systemd-resolved[798]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:27:35 green systemd-resolved[798]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    Aug 06 10:27:35 green systemd-resolved[798]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature
    

    systemd-resolve --status shows the same as before.

    • Admin
      Admin almost 5 years
      Try systemctl enable and an implicit systemctl start.
    • Admin
      Admin almost 5 years
      you have to run systemctl enable... every time you reboot?
    • Admin
      Admin almost 5 years
      @heynnema As you can see, I've tried systemctl enable. Unfortunately, it only starts the resolver, but doesn't keep it running after a reboot.
    • Admin
      Admin almost 5 years
      @JoshuaBesneatte I can run systemctl start too. Using enable is supposed to persist, but doesn't.
    • Admin
      Admin almost 5 years
      Are you using sudo?
    • Admin
      Admin almost 5 years
      @heynnema as shown in the output above, the commands are being run from a root shell.
    • Admin
      Admin almost 5 years
      I've seen some commands... like fsck not work from a # prompt without the use of sudo. Try sudo systemctl enable... and sudo systemctl start... and see if it makes any difference.
    • Admin
      Admin almost 5 years
      The # prompt came from sudo -s. I understand you are trying to be helpful, but you're just making random guesses at this point.
    • Admin
      Admin almost 5 years
      Did you had a look to boot logs? Maybe the service starts and stops or fails to start... Did you check the status before and after reboot to get enabled/disabled property?
    • Admin
      Admin almost 5 years
      @cmak.fr Nothing in syslog looks related. I updated the question with a log excerpt.
    • Admin
      Admin almost 5 years
      og seems to show that the service is running... what about status ?
    • Admin
      Admin almost 5 years
      @cmak.fr I've added the output of systemctl status as it was, immediately after a reboot, and after I manually ran enable.
    • Admin
      Admin almost 5 years
      Your /etc/resolv.conf is probably wrong. See askubuntu.com/questions/1163760/… for the solution.
    • Admin
      Admin almost 5 years
      @ubfan1 resolv.conf is generated by the system. I'm not editing it manually.
    • Admin
      Admin almost 5 years
      You installed something like resolvconf which cuts sytemd-resolved off entirely by comment out the 53 listening address in stub-recolv.conf which the /etc/resolv.conf should link to.For a fresh Ubuntu 18.04 install, the only additional name resolution package I needed was libnss-resolve. I never use resolvconf, so don't know why you need it.
    • Admin
      Admin almost 5 years
      @ubfan1 apt remove resolvconf fixed it. Can you post as an answer so I can accept it?
    • Admin
      Admin about 4 years
      the solution is here askubuntu.com/a/1231591/828892