Questions[connman](ubuntu)

I have just installed LXQT on top of a fresh install of Ubuntu server cosmic 18.10.

It uses connman-ui as the wifi/network manager.

If I plug an ethernet cable in and enable wifi at the same time then DNS might work. If I plug an ethernet cable in and disable wifi then DNS always works. If I unplug the ethernet cable and enable wifi then DNS does not work.

Concentrating on the wifi only case:-

If I go to connman UI Setup and the Details tab it says Service Type: Wifi and Name Servers 192.168.1.254 which is correct (that's my BT Homehub) and I can ping 192.168.1.254.

If I go to /etc/resolv.conf it says nameserver 127.0.0.53

If I check with netstat -nlp |grep 53 it says

tcp        0      0 127.0.0.1:53            0.0.0.0:*               LISTEN      1202/connmand       
tcp        0      0 127.0.0.53:53           0.0.0.0:*               LISTEN      1001/systemd-resolv 

Next, using systemd-resolve --status I get

Link 3 (wlp3s0b1)
      Current Scopes: none
       LLMNR setting: yes
MulticastDNS setting: no
  DNSOverTLS setting: no
      DNSSEC setting: no
    DNSSEC supported: no

Link 2 (enp2s0)
      Current Scopes: none
       LLMNR setting: yes
MulticastDNS setting: no
  DNSOverTLS setting: no
      DNSSEC setting: no
    DNSSEC supported: no

Now, if I enable ethernet again I get:-

Link 3 (wlp3s0b1)
      Current Scopes: none
       LLMNR setting: yes
MulticastDNS setting: no
  DNSOverTLS setting: no
      DNSSEC setting: no
    DNSSEC supported: no

Link 2 (enp2s0)
      Current Scopes: DNS
       LLMNR setting: yes
MulticastDNS setting: no
  DNSOverTLS setting: no
      DNSSEC setting: no
    DNSSEC supported: no
  Current DNS Server: 192.168.1.254
         DNS Servers: 192.168.1.254
          DNS Domain: home

The exact same setup on another laptop (a Lenovo T420s) with Debian stretch is reliable on wifi.

Another laptop (a Lenovo T470) also with Cosmic 18.10 and LXQT is reliable on wifi Edit: sorry this is a red herring. I just looked in /etc/resolv.conf at it's set to 8.8.8.8. I think I hacked it and forgot that I did so.

This laptop (a Macbook Pro 8,3) has been not reliable with both Debian Sid and with Cosmic 18.10.

I would like to report this as a bug somewhere but I'm not really sure which package is causing the problem. Is it connmand, systemd-resolve, or the wifi driver?

Edit2:- if someone is using LXQT and just wants a pragmatic fix then this seems to work:-

systemctl disable systemd-resolved
systemctl stop systemd-resolved
mv resolv.conf resolv.conf.systemd
echo "nameserver 127.0.0.1" > /etc/resolv.conf

this just disables systemd-resolve and used connmand as an internal DNS server, which is probably what you wanted if you are using connman UI setup.

Back to my original question I'm not sure if it just that the original build is using "server" edition and that systemd-resolve is appropriate to a server build and not a laptop, or whether installation of connmand should disable it.

The reason that I use the server edition is that I don't want to have to remove all of the gnome guff before installing LXQT and the server edition seems to be the easiest way to get there.

Every time that I start my computer, my DNS does not work. In /etc/resolv.conf I see:

# Generated by Connection Manager
nameserver ::1
nameserver 127.0.0.1

I see that /etc/resolv.conf is a soft link to /run/connman/resolv.conf

With this configuration, my DNS does not work (example: cannot surf the web with Chrome/Firefox, dig google.com gives me no IP, and ping gives me "Name or service not known"). So, I manually change the nameserver ::1 with some valid IP (like 1.1.1.1 or 8.8.8.8). I need to do this every time that I turn on my computer.

I don't know if connman (Intel Connection Manager daemon) comes preinstalled in Ubuntu 17.10, or I have installed it when trying to install a VPN client. Searching on the web, it seems that I don't have a standard configuration. So, I tried stopping the service, but then I lose my connections and don't see the available networks in the (NetworkManager?) Applet.

I can see that connmand is listening on port 53 (but does not resolve well), and systemd-resolve is also listening on port 53 (but attached to 127.0.0.53):

sudo netstat -tulpn | grep ":53 "
tcp        0      0 127.0.0.1:53            0.0.0.0:*               LISTEN      21159/connmand      
tcp6       0      0 ::1:53                  :::*                    LISTEN      21159/connmand      
udp        0      0 127.0.0.1:53            0.0.0.0:*                           21159/connmand      
udp        0      0 127.0.0.53:53           0.0.0.0:*                           1451/systemd-resolv 
udp6       0      0 ::1:53                  :::*                                21159/connmand

If I execute systemd-resolve --status, it gives me the correct DNS.

Relinking /etc/resolv.conf to /run/systemd/resolve/resolv.conf also solves my problem.

So, how can I disable connman (at least as the DNS proxy) and reenable systemd-resolve? Is connman installed by default on Ubuntu 17.10?

I posted a question a little while ago about the network icon no longer showing in the indicator applet after upgrading to maverick. After reading this post, I looked in synaptic to see if I was missing any of the indicators, and it showed that indicator-network wasn't installed, so I installed it. Restarted my computer, and now all my network devices are gone.

I removed the indicator applet from the panel, but still have AWN running, so I looked at the network icon there. When I click on it, instead of showing me all my wireless network options, all it shows is "No network devices available" (greyed out), and "VPN connections" with an available submenu of "Configure VPN".

When I open the Network Connections dialog through the System Preferences menu, it shows a list of connections accessed in the past, including the wireless network I want to be connected to (and which was connected as of 8 minutes ago.)

What did I do? As far as I know all I did was install an indicator icon, so why did it completely delete my network stuff? And more importantly, how can I get it back?

This is a small nuisance I've had in Ubuntu forever. When I set my computer to login automatically, Network Manager asks me for my keyring password every time it boots and it refuses to connect to the Internet until I enter it. Is there a reason for that?

Also, other network managers such as Connman don't have this problem, and I have noticed the latter also has an application indicator while NM-applet runs in the Notification Area. Are there plans to migrate to Connman, or to adapt NM-applet for Natty?

In the 10.10 release, Unity on the netbook edition used ConnMan. As Unity is now moving to the desktop for 11.04, will that mean that ConnMan will replace NetworkManager on the default Ubuntu desktop as well?