[Bug 1729194] Re: Systemd-Resolvd Forgets to Resolv Request

[Steve Langasek]

127.0.1.1 is not the address of systemd-resolved, as you noted; it's the
address used by dnsmasq.  It sounds like your network-manager config is
pointing to dnsmasq, which is no longer the default in 17.10, and should
have been dropped from your config on upgrade from 16.10 to 17.04.  Can
you please attach the /etc/NetworkManager/NetworkManager.conf from the
affected system?

** Package changed: systemd (Ubuntu) => network-manager (Ubuntu)

** Summary changed:

- Systemd-Resolvd Forgets to Resolv Request
+ /etc/resolv.conf pointing to dnsmasq instead of resolved

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1729194

Title:
  /etc/resolv.conf pointing to dnsmasq instead of resolved

Status in network-manager package in Ubuntu:
  Confirmed

Bug description:
  Systemd sometimes just doesn't resolve DNS queries and for the life of
  me I don't know why.

  So often when I'm switching between wifi networks I find that systemd-
  resolved in 17.10 complete fails to do it's job. Here's the example.
  I'm connected to the internet :

  ```
  chalbersma at nebraska [~] {Tue Oct 31 20:58:18}        
  > ping 8.8.8.8            
  PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.         
  64 bytes from 8.8.8.8: icmp_seq=1 ttl=53 time=196 ms 
  64 bytes from 8.8.8.8: icmp_seq=2 ttl=53 time=67.5 ms                                                     
  64 bytes from 8.8.8.8: icmp_seq=3 ttl=53 time=78.9 ms                                                     
  ^C                        
  --- 8.8.8.8 ping statistics ---                      
  3 packets transmitted, 3 received, 0% packet loss, time 1999ms                                            
  rtt min/avg/max/mdev = 67.534/114.169/196.025/58.068 ms
  ```

  But I can't seem to resolve domains:

  ```
  chalbersma at nebraska [~] {Tue Oct 31 20:59:17}        
  > nslookup google.com
  ;; connection timed out; no servers could be reached

  ```

  So I did a `systemd-resolver --status` to see if it's getting the
  right dns server. It is :

  ```
  Link 3 (wlp2s0)                                      
        Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6      
         LLMNR setting: yes                            
  MulticastDNS setting: no                             
        DNSSEC setting: no                             
      DNSSEC supported: no                             
           DNS Servers: 192.168.43.1                   
                        2001:4888:51:ff00:506:d::      
                        2001:4888:50:ff00:500:d::

  ```

  And it's actually up and working properly :

  ```
  chalbersma at nebraska [~] {Tue Oct 31 21:02:06}
  > nslookup google.com 192.168.43.1
  Server:         192.168.43.1
  Address:        192.168.43.1#53

  Non-authoritative answer:
  Name:   google.com
  Address: 172.217.11.78
  chalbersma at nebraska [~] {Tue Oct 31 21:03:16}
  > nslookup google.com 2001:4888:51:ff00:506:d::
  Server:         2001:4888:51:ff00:506:d::
  Address:        2001:4888:51:ff00:506:d::#53

  Non-authoritative answer:
  Name:   google.com
  Address: 172.217.11.78
  ```

  Systemd just can't figure out to make the request. I did try the
  common step of flushing the cache (with `--flush-cache`) restarting
  network-manager and systemd-resolverd service but nothing seems to be
  able to make systemd-resolverd function. Even a reboot doesn't always
  fix the issue; sometimes it persists.

  For debugging this is what's in my /etc/resolv.conf :

  ```  
  chalbersma at nebraska [~] {Tue Oct 31 21:09:15} 
  > cat /etc/resolv.conf                        
  # Generated by NetworkManager                 
  nameserver 127.0.1.1      
  ```

  As soon as I manually set the nameserver from my loopback to the
  actual dns server (bypassing systemd-resolvd) things start working
  again. Let me know what kind of tshooting data I'd need to grab to
  help display this issue.

  In order to restore networking I had to manually edit that file and
  change my dns to the external source.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1729194/+subscriptions