Wrong nameserver set by resolvconf and NetworkManager
My DNS server is 192.168.1.152.
This DNS is provided to clients by DHCP. The windows clients on my LAN resolve names properly using that DNS, but my Ubuntu VM doesn't.
The VM is set up with bridge networking and is being properly provided the DNS server, but my local hostnames aren't being resolved by nslookup or browsers.
Here is an nslookup of one of my local domains:
# nslookup unraid.local
Server: 127.0.0.53
Address: 127.0.0.53#53
** server can't find unraid.local: SERVFAILHere is what it should resolve by using my DNS server:
# nslookup unraid.local 192.168.1.152
Server: 192.168.1.152
Address: 192.168.1.152#53
Name: unraid.local
Address: 192.168.1.152/etc/resolv.conf has a wrong nameserver:
# 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 127.0.0.53I ran that command. Under DNS Servers, confusingly, it specifies the correct server (and my default gateway).
root@ubuntu:~# systemd-resolve --status
Global 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 2 (ens33) Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6 LLMNR setting: yes
MulticastDNS setting: no DNSSEC setting: no DNSSEC supported: no DNS Servers: 192.168.1.152 192.168.1.1I don't want to "hard code" the DNS server's IP in a config file because I won't be able to resolve when I change networks.
How can I get resolvconf and NetworkManager to automatically set the DHCP server's IP in /etc/resolv.conf?
12 Answers
Temporary workaround with no need to reconfigure if the DNS IP's changes:
sudo rm -f /etc/resolv.conf
sudo ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf
rebootTry editing /etc/systemd/resolved.conf, adding your desired DNS server:
change this:
[Resolve]
#DNS=to this (but use the one you want - this is an example):
[Resolve]
DNS=192.168.1.152after that, restart the service:
service systemd-resolved restartAnd when you check the status you should see
$ systemd-resolve --status
Global DNS Servers: 192.168.1.152 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.arpaI finally got a solution for this problem for ubuntu 17.10. By default this version of Ubuntu uses systemd-resolved, which I hope is going to be stable for the next versions.
In order to use custom dns instead of the local systemd-resolved cache, do the following:
add new nameservers. Edit the file in
/etc/systemd/resolved.confas sudoer. Here I've commented out the DNS entry and placed my dns[Resolve] DNS=10.96.0.10 8.8.8.8 8.8.4.4cancel the actual symlink to
/etc/resolv.conf- create a new symlink
sudo ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf - restart the service
sudo service systemd-resolved restart - restart the network manager
sudo systemctl restart networking
And now if you dig to a name provided by your add dns, you should see the record resolved dig nexus.default.svc.cluster.mydomain
Last step is to update the order of resolution in /etc/nsswitch.conf, by placing the dns before the mdns4_minimal
hosts files dns mdns4_minimal [NOTFOUND=return] resolve [!UNAVAIL=return] myhostnameYour /etc/resolv.conf is not the problem. systemd-resolved just defaults to unconfigured, so it fails all lookups. Feel free to rant about Unconfigured vs A Reasonable Default.
Manually add nameservers to systemd-resolved.
(editing per Olorin's comment below to add mkdir, correct path /etc not /lib, in order to survive system updates)
sudo mkdir -p /etc/systemd/resolved.conf.d
sudo nano /etc/systemd/resolved.conf.d/00-my-dns-server-is.confAdd:
[Resolve]
Cache=yes
DNS=192.168.1.152Then...
sudo systemctl daemon-reloadsystemd-resolved is smart, but, unconfigured as it is, by package maintainers, it just LOOKS stupid because package maintainers do not believe in A Reasonable Default. We can put 13 internet root servers in there aka "djb way", or 10 opennic servers: or the three fastest opennic servers, as measured by namebench. Plus ISP nameservers, sure. Plus Google, sure. systemd-resolved is not the problem. I am the problem.
On my system I found a bad symlink: /etc/resolv.conf was a symlink which points to /run/systemd/resolve/stub-resolv.conf
This file contains only one line:
nameserver 127.0.0.53#53As a result, the local network's DNS lookup was often missing.
So, instead I changed /etc/reolv.conf to point to /run/systemd/resolve/resolv.conf
and now works correctly.
I put together a script that works around the issue of Netplan not currently supporting the ability to supersede DHCP supplied DNS servers and domain search order. It creates the Netplan yaml file and configures systemd-resolved to work as expected.
################## Start Netplan config (renderer: NetworkManager)
# Some useful commands for customisation
# NetConn=$(nmcli device show|grep GENERAL.CONNECTION|head -n1|awk '{print $2}')
# IP=$(nmcli device show|grep IP4.ADDRESS|head -n1|awk '{print $2}')
# GATEWAY=$(nmcli device show|grep IP4.GATEWAY|head -n1|awk '{print $2}')
# sed -i 's/renderer: networkd/renderer: NetworkManager/' //etc/netplan/01-netcfg.yaml
######################################
systemctl start NetworkManager
NIC=$(nmcli device show|grep GENERAL.DEVICE|head -n1|awk '{print $2}')
##### create Netplan yaml config file
cat >/etc/netplan/01-netcfg.yaml <<EOF
# This file describes the network interfaces available on your system
# For more information, see netplan(5). network: version: 2 renderer: NetworkManager ethernets:
EOF
echo " ${NIC}:" >> /etc/netplan/01-netcfg.yaml
cat >>/etc/netplan/01-netcfg.yaml <<EOF dhcp4: yes nameservers: search: [abc.domain.edu, def.domain.edu] addresses: [10.10.11.22, 10.10.11.23]
EOF
#work around DNS resolv bug
systemctl stop systemd-resolved
sed -i 's/#DNS=/DNS=10.10.11.22 10.10.11.23/' /etc/systemd/resolved.conf
sed -i 's/#Domains=/Domains=abc.domain.edu def.domain.edu' /etc/systemd/resolved.conf
systemctl start systemd-resolved
systemctl restart NetworkManager
netplan apply
reboot
############### End Netplan ConfigThe solution that worked for me is posted here on my blog
Use nano editor to edit these 2 files
nano /etc/resolv.conf
nano /etc/resolvconf/resolv.conf.d/headAdd DNS servers you want to use
nameserver 9.9.9.9
nameserver 127.0.0.1Then restart the service
service systemd-resolved restartFinal check:
cat /etc/resolv.confDo nslookup
nslookup google.com i just used this and it fixed the problem on my laptop at home, but some time in the future when I am out of my home network I can see that it will cause problems, because the primary and secondary dns server will still be my home servers with their lan addresses.
3It's strange but the only solution which worked for me on Ubuntu 18.04 was the one I found here:
First, change /etc/resolv.conf by setting the desired nameserver:
# nano /etc/resolv.confSet, for instance,
nameserver 8.8.8.8And then do
# chattr +i /etc/resolv.confThis protects /etc/resolv.conf file so that no one can modify it including root user.
I just went through this again on another machine. I decided to live with systemd's resolved and with networkmanager by editing the resolved.conf file, /etc/systemd/resolved.conf, and setting networkmanager to use the same dns server. Stop the stub listener from taking over dns:
/etc/systemd/resolved.conf:
[Resolve]
DNS=192.168.0.1
#FallbackDNS=
#Domains=
#LLMNR=no
#MulticastDNS=no
#DNSSEC=no
#Cache=yes
DNSStubListener=no...then go into NetworkManager and stop nm from using dhcp to acquire a nameserver IP. Turn off Automatic for DNS, set the nameserver IP.
I've only been able to get name resolution to work with Docker by disabling systemd-resolved completely:
systemctl stop systemd-resolved
systemctl disable systemd-resolvedThen edit /etc/resolv.conf like you would have back in the pre-systemd days.
What I did, after this happened to me when I upgraded from a much older Ubuntu release and my name resolution broke. First I tried the 00-yadayadayada approach above - but that did NOT work.
cd /etc mv resolv.conf resolv.conf-I-HATE-SYSTEMD cp resolv.conf-I-HATE-SYSTEMD resolv.conf
And then edited the file /etc/resolv.conf. The first gets rid of the pesky symbolic link (and documents that was done) so that subsequent reboots won't overwrite it (I hope).
What all of this demonstrates is THE ABSOLUTE FOLLY THAT IS SYSTEMD. What the fsck does a resolver configuration have to do with system startup order, etc., such that systemd should be involved AT ALL. What a piece of junk.ARRRRRRRRGH. What a piece of junk systemd is. Too many programmers with too much time on their hands to lazy to do the "un fun" jobs of actually writing and fixing APPLICATIONS, seeing it as somehow "beneath" them. Bah.
JRJ
I have the same problem. Each reboot, nothing will resolve. I've uninstalled everything and reinstalled it about 50 times already. It's simply just broken.
so the fix is.... "just apply a few settings each time you boot your pc, which allows 90% of host names to resolve but wget and apt-get updates and upgrades will fail randomly for no reason"
cat /etc/systemd/resolved.conf
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See resolved.conf(5) for details
[Resolve]
#DNS=
#FallbackDNS=
#Domains=
#LLMNR=yes
#MulticastDNS=yes
#DNSSEC=no
#Cache=yes
#DNSStubListener=udpWhen using Ubuntu 17.10 Desktop, you have to edit the one file that says DO NOT EDIT THIS FILE BLAH BLAH BLAH
well that's the ONLY way it works~!
root@nas:~# cat /etc/resolv.conf
# This file is managed by man:systemd-resolved(8). Do not edit.
#
# 127.0.0.53 is the systemd-resolved stub resolver.
# run "systemd-resolve --status" to see details about the actual nameservers.
nameserver 8.8.8.8So remove the 127.0.0.53 IP as the name server and enter another one, google for example. It appears my actual DNS IP address doesn't resolve host names either (even though it works on 10 other machines and devices in the house), but google's works fine.
