DNS resolving not working due to wrong entry in resolv.conf

[thet]

In my ``/etc/resolv.conf`` I have the entry:

```
nameserver 127.0.0.53
```

I'm connected to the network via WIFI.
My IP is ``192.168.0.31``

The network-manager applet shows me automatic DNS configuration and a DNS server of 192.0.0.1, which is correct.
Changing DNS configuration in the network-manager applet to manual and editing it there doesn't work either.

I have to edit the resolv.conf file in order to get DNS resolving work.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: network-manager 1.10.6-2ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-13.14-generic 4.15.10
Uname: Linux 4.15.0-13-generic x86_64
ApportVersion: 2.20.9-0ubuntu4
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Wed Apr 11 11:51:58 2018
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2018-04-09 (1 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Beta amd64 (20180404)
IpRoute:
 default via 192.168.0.1 dev wlp1s0 proto dhcp metric 20600
 169.254.0.0/16 dev wlp1s0 scope link metric 1000
 192.168.0.0/24 dev wlp1s0 proto kernel scope link src 192.168.0.31 metric 600
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-con:
 NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT AUTOCONNECT-PRIORITY READONLY DBUS-PATH ACTIVE DEVICE STATE ACTIVE-PATH SLAVE
 NSACIAGCHQ5 f8431fbb-6f3c-4848-bcc4-4449012df3f7 wifi 1523440039 Mi 11 Apr 2018 11:47:19 CEST yes 0 no /org/freedesktop/NetworkManager/Settings/2 yes wlp1s0 activated /org/freedesktop/NetworkManager/ActiveConnection/1 --
 welansepp af2f9fd1-2a81-4e2c-95e5-3f4e9a9997b9 wifi 1523402504 Mi 11 Apr 2018 01:21:44 CEST yes 0 no /org/freedesktop/NetworkManager/Settings/1 no -- -- -- --
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH
 wlp1s0 wifi connected /org/freedesktop/NetworkManager/Devices/2 NSACIAGCHQ5 f8431fbb-6f3c-4848-bcc4-4449012df3f7 /org/freedesktop/NetworkManager/ActiveConnection/1
 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/1 -- -- --
nmcli-nm:
 RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
 running 1.10.6 connected (site only) started limited enabled enabled enabled enabled enabled

[thet (thet)]

More on this:

After a fresh reboot but also after wake from suspend I have to set the DNS server in /etc/resolv.conf manually to get DNS resolving working.

This is the output of ``systemd-resolve --status`` before manual changes:

root@thettop:~# 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 4 (virbr0-nic)
      Current Scopes: none
       LLMNR setting: yes
MulticastDNS setting: no
      DNSSEC setting: no
    DNSSEC supported: no

Link 3 (virbr0)
      Current Scopes: none
       LLMNR setting: yes
MulticastDNS setting: no
      DNSSEC setting: no
    DNSSEC supported: no

Link 2 (wlp1s0)
      Current Scopes: DNS
       LLMNR setting: yes
MulticastDNS setting: no
      DNSSEC setting: no
    DNSSEC supported: no
         DNS Servers: 192.168.0.1
          DNS Domain: local

And this is the content of /etc/resolv.conf before any manual changes:

thet@thettop:~$ more /etc/resolv.conf
# This file is managed by man:systemd-resolved(8). Do not edit.
#
# This is a dynamic resolv.conf file for connecting local clients to the
# internal DNS stub resolver of systemd-resolved. This file lists all
# configured search domains.
#
# Run "systemd-resolve --status" to see details about the uplink DNS servers
# currently in use.
#
# Third party programs must not access this file directly, but only through the
# symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a different way,
# replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.

nameserver 127.0.0.53
search local

[thet (thet)]

Works now.

[thet (thet)]

Nope. Still an issue.

[thet (thet)]

Fixed - The symlink of resolv.conf was wrong. The following shows how - resolv.conf-BAK was the old, broken one, resolv.conf the one I fixed. I don't know how that happened, but I have installed the 18.04 beta version, may that was the reason.

lrwxrwxrwx 1 root root 32 Mai 29 10:55 resolv.conf -> /run/systemd/resolve/resolv.conf
lrwxrwxrwx 1 root root 39 Apr 9 12:26 resolv.conf-BAK -> ../run/systemd/resolve/stub-resolv.conf