systemd-resolved not starting on boot
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.
Paul Schreiber
Updated on September 18, 2022Comments
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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 almost 5 yearsTry
systemctl enable
and an implicitsystemctl start
. -
Admin almost 5 yearsyou have to run
systemctl enable...
every time you reboot? -
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 almost 5 years@JoshuaBesneatte I can run
systemctl start
too. Usingenable
is supposed to persist, but doesn't. -
Admin almost 5 yearsAre you using
sudo
? -
Admin almost 5 years@heynnema as shown in the output above, the commands are being run from a root shell.
-
Admin almost 5 yearsI've seen some commands... like
fsck
not work from a # prompt without the use ofsudo
. Trysudo systemctl enable...
andsudo systemctl start...
and see if it makes any difference. -
Admin almost 5 yearsThe
#
prompt came fromsudo -s
. I understand you are trying to be helpful, but you're just making random guesses at this point. -
Admin almost 5 yearsDid 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 almost 5 years@cmak.fr Nothing in syslog looks related. I updated the question with a log excerpt.
-
Admin almost 5 yearsog seems to show that the service is running... what about status ?
-
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 almost 5 yearsYour /etc/resolv.conf is probably wrong. See askubuntu.com/questions/1163760/… for the solution.
-
Admin almost 5 years@ubfan1 resolv.conf is generated by the system. I'm not editing it manually.
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Admin almost 5 yearsYou 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 almost 5 years@ubfan1
apt remove resolvconf
fixed it. Can you post as an answer so I can accept it? -
Admin about 4 yearsthe solution is here askubuntu.com/a/1231591/828892