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how does DNS work with systemd connman lxqt in sid?

Linux Kernel, Network, and Services configuration.
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dieselnutjob
Posts: 133
Joined: 2011-04-12 10:25

how does DNS work with systemd connman lxqt in sid?

#1 Post by dieselnutjob »

I have played a bit with LXQT for a while, but this is the first time that I have done a clean install of sid.

I have put a second hard drive into my old Macbookpro 8,3 and installed sid with no gui
Then I got xorg to work
Then I installed lxqt

This was all working fine at home, but then I was in a hotel and could not get the hotel wifi to work. Specifically I got an IP address but no DNS server so nothing would work.
Booting OSX it went onto the hotel hotspot and got DNS as well.

Then I tried figuring out what was wrong and how to fix it and realised that my knowledge of linux since systemd is really not enough and I don't understand how it works.

Now I am back home and wifi is working again. DNS lookups are working yet there are no DNS servers in /etc/resolv.conf. I don't understand how it works.
I notice that I appear to have avahi-daemon and avahi-autoipd installed.

Would someone mind explained how DNS now works in sid in a DHCP / wifi environment?

Edit: it is using cmst rather than network-manager

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Head_on_a_Stick
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Re: how does DNS work with systemd connman lxqt in sid?

#2 Post by Head_on_a_Stick »

dieselnutjob wrote:there are no DNS servers in /etc/resolv.conf
Please post the full content of /etc/resolv.conf and also the output of

Code: Select all

systemctl list-unit-files --state=enabled
deadbang

milomak
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Re: how does DNS work with systemd connman lxqt in sid?

#3 Post by milomak »

Would someone mind explained how DNS now works in sid in a DHCP / wifi environment?
i have never noticed sid to work differently from stable in this regard

on my laptop i have installed stable first. then from there upgraded to sid.
Desktop: A320M-A PRO MAX, AMD Ryzen 5 3600, GALAX GeForce RTX™ 2060 Super EX (1-Click OC) - Sid, Win10, Arch Linux, Gentoo, Solus
Laptop: hp 250 G8 i3 11th Gen - Sid
Kodi: AMD Athlon 5150 APU w/Radeon HD 8400 - Sid

dieselnutjob
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Re: how does DNS work with systemd connman lxqt in sid?

#4 Post by dieselnutjob »

Code: Select all

@macbookpro83:~$ cat /etc/resolv.conf 
domain home
search home

@macbookpro83:~$ systemctl list-unit-files --state=enabled
UNIT FILE                                  STATE  
anacron.service                            enabled
apparmor.service                           enabled
autovt@.service                            enabled
avahi-daemon.service                       enabled
bluetooth.service                          enabled
connman-wait-online.service                enabled
connman.service                            enabled
console-setup.service                      enabled
cron.service                               enabled
dbus-fi.w1.wpa_supplicant1.service         enabled
dbus-org.bluez.service                     enabled
dbus-org.freedesktop.Avahi.service         enabled
dbus-org.freedesktop.ModemManager1.service enabled
dundee.service                             enabled
getty@.service                             enabled
haveged.service                            enabled
irqbalance.service                         enabled
keyboard-setup.service                     enabled
ModemManager.service                       enabled
networking.service                         enabled
ofono.service                              enabled
rsyslog.service                            enabled
ssh.service                                enabled
sshd.service                               enabled
syslog.service                             enabled
systemd-timesyncd.service                  enabled
udisks2.service                            enabled
wpa_supplicant.service                     enabled
avahi-daemon.socket                        enabled
remote-fs.target                           enabled
anacron.timer                              enabled
apt-daily-upgrade.timer                    enabled
apt-daily.timer                            enabled
logrotate.timer                            enabled

34 unit files listed.

dieselnutjob
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Joined: 2011-04-12 10:25

Re: how does DNS work with systemd connman lxqt in sid?

#5 Post by dieselnutjob »

I am starting to understand now

Code: Select all

@macbookpro83:~$ nslookup
> server
Default server: 127.0.0.1
Address: 127.0.0.1#53
Default server: ::1
Address: ::1#53

Code: Select all

@macbookpro83:~$ sudo ss -nlput
Netid State   Recv-Q  Send-Q     Local Address:Port      Peer Address:Port                                           
udp   UNCONN  0       0           127.0.0.1%lo:53             0.0.0.0:*      users:(("connmand",pid=607,fd=11))      
udp   UNCONN  0       0                0.0.0.0:68             0.0.0.0:*      users:(("dhclient",pid=974,fd=6))       
udp   UNCONN  0       0                0.0.0.0:5353           0.0.0.0:*      users:(("chrome",pid=988,fd=190))       
udp   UNCONN  0       0                0.0.0.0:5353           0.0.0.0:*      users:(("chrome",pid=988,fd=87))        
udp   UNCONN  0       0                0.0.0.0:5353           0.0.0.0:*      users:(("avahi-daemon",pid=612,fd=12))  
udp   UNCONN  0       0                0.0.0.0:43019          0.0.0.0:*      users:(("avahi-daemon",pid=612,fd=14))  
udp   UNCONN  0       0                   [::]:40806             [::]:*      users:(("avahi-daemon",pid=612,fd=15))  
udp   UNCONN  0       0               [::1]%lo:53                [::]:*      users:(("connmand",pid=607,fd=12))      
udp   UNCONN  0       0                      *:5353                 *:*      users:(("chrome",pid=988,fd=147))       
udp   UNCONN  0       0                   [::]:5353              [::]:*      users:(("avahi-daemon",pid=612,fd=13))  
tcp   LISTEN  0       10          127.0.0.1%lo:53             0.0.0.0:*      users:(("connmand",pid=607,fd=13))      
tcp   LISTEN  0       128              0.0.0.0:22             0.0.0.0:*      users:(("sshd",pid=672,fd=5))           
tcp   LISTEN  0       10              [::1]%lo:53                [::]:*      users:(("connmand",pid=607,fd=14))      
tcp   LISTEN  0       128                 [::]:22                [::]:*      users:(("sshd",pid=672,fd=6)) 
so it seems that DNS queries are handled by connmand

I am still used to using ifconfig and netstat. All the old commands that are deprecated and having to learn new ones is making me feel old.

milomak
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Re: how does DNS work with systemd connman lxqt in sid?

#6 Post by milomak »

i don't think your posit is entirely correct

# ss -nlput

Code: Select all

Netid          State            Recv-Q           Send-Q                      Local Address:Port                      Peer Address:Port                                                                             
udp            UNCONN           0                0                                 0.0.0.0:5353                           0.0.0.0:*              users:(("avahi-daemon",pid=690,fd=12))                            
udp            UNCONN           0                0                                 0.0.0.0:5355                           0.0.0.0:*              users:(("systemd-resolve",pid=634,fd=11))                         
udp            UNCONN           0                0                                 0.0.0.0:56842                          0.0.0.0:*              users:(("avahi-daemon",pid=690,fd=14))                            
udp            UNCONN           0                0                           127.0.0.53%lo:53                             0.0.0.0:*              users:(("systemd-resolve",pid=634,fd=16))                         
udp            UNCONN           0                0                                 0.0.0.0:68                             0.0.0.0:*              users:(("dhclient",pid=1316,fd=6))                                
udp            UNCONN           0                0                                 0.0.0.0:111                            0.0.0.0:*              users:(("rpcbind",pid=632,fd=5),("systemd",pid=1,fd=30))          
udp            UNCONN           0                0                                 0.0.0.0:538                            0.0.0.0:*              users:(("gdomap",pid=720,fd=4))                                   
udp            UNCONN           0                0                                 0.0.0.0:631                            0.0.0.0:*              users:(("cups-browsed",pid=817,fd=7))                             
udp            UNCONN           0                0                                 0.0.0.0:1900                           0.0.0.0:*              users:(("minissdpd",pid=1417,fd=4))                               
udp            UNCONN           0                0                                    [::]:5353                              [::]:*              users:(("avahi-daemon",pid=690,fd=13))                            
udp            UNCONN           0                0                                    [::]:5355                              [::]:*              users:(("systemd-resolve",pid=634,fd=13))                         
udp            UNCONN           0                0                                    [::]:111                               [::]:*              users:(("rpcbind",pid=632,fd=7),("systemd",pid=1,fd=32))          
udp            UNCONN           0                0                                       *:1716                                 *:*              users:(("kdeconnectd",pid=4167,fd=19))                            
udp            UNCONN           0                0                                    [::]:1900                              [::]:*              users:(("minissdpd",pid=1417,fd=5))                               
udp            UNCONN           0                0                                    [::]:42878                             [::]:*              users:(("avahi-daemon",pid=690,fd=15))                            
tcp            LISTEN           0                128                               0.0.0.0:5355                           0.0.0.0:*              users:(("systemd-resolve",pid=634,fd=12))                         
tcp            LISTEN           0                128                               0.0.0.0:111                            0.0.0.0:*              users:(("rpcbind",pid=632,fd=4),("systemd",pid=1,fd=29))          
tcp            LISTEN           0                128                             127.0.0.1:41937                          0.0.0.0:*              users:(("expressvpn-brow",pid=4146,fd=7))                         
tcp            LISTEN           0                128                               0.0.0.0:22                             0.0.0.0:*              users:(("sshd",pid=832,fd=3))                                     
tcp            LISTEN           0                5                               127.0.0.1:631                            0.0.0.0:*              users:(("cupsd",pid=678,fd=7))                                    
tcp            LISTEN           0                20                              127.0.0.1:25                             0.0.0.0:*              users:(("exim4",pid=1843,fd=3))                                   
tcp            LISTEN           0                16                                0.0.0.0:538                            0.0.0.0:*              users:(("gdomap",pid=720,fd=5))                                   
tcp            LISTEN           0                128                             127.0.0.1:2015                           0.0.0.0:*              users:(("expressvpnd",pid=1404,fd=5))                             
tcp            LISTEN           0                128                             127.0.0.1:33985                          0.0.0.0:*              users:(("expressvpn-brow",pid=5811,fd=6))                         
tcp            LISTEN           0                50                              127.0.0.1:6341                           0.0.0.0:*              users:(("megasync",pid=4418,fd=32))                               
tcp            LISTEN           0                50                              127.0.0.1:6342                           0.0.0.0:*              users:(("megasync",pid=4418,fd=37))                               
tcp            LISTEN           0                128                                  [::]:5355                              [::]:*              users:(("systemd-resolve",pid=634,fd=14))                         
tcp            LISTEN           0                128                                  [::]:111                               [::]:*              users:(("rpcbind",pid=632,fd=6),("systemd",pid=1,fd=31))          
tcp            LISTEN           0                50                                      *:1716                                 *:*              users:(("kdeconnectd",pid=4167,fd=20))                            
tcp            LISTEN           0                128                                  [::]:22                                [::]:*              users:(("sshd",pid=832,fd=4))                                     
tcp            LISTEN           0                5                                   [::1]:631                               [::]:*              users:(("cupsd",pid=678,fd=6))                                    
tcp            LISTEN           0                20                                  [::1]:25                                [::]:*              users:(("exim4",pid=1843,fd=4))
Desktop: A320M-A PRO MAX, AMD Ryzen 5 3600, GALAX GeForce RTX™ 2060 Super EX (1-Click OC) - Sid, Win10, Arch Linux, Gentoo, Solus
Laptop: hp 250 G8 i3 11th Gen - Sid
Kodi: AMD Athlon 5150 APU w/Radeon HD 8400 - Sid

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Re: how does DNS work with systemd connman lxqt in sid?

#7 Post by Head_on_a_Stick »

dieselnutjob wrote:DNS queries are handled by connman
That's what the package description implies:
ConnMan implements DNS resolving and caching
https://packages.debian.org/stretch/connman
deadbang

dieselnutjob
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Re: how does DNS work with systemd connman lxqt in sid?

#8 Post by dieselnutjob »

So do "normal" TCP/IP enabled applications have the in built ability to do DNS lookups by looking up the server in /etc/resolv.conf and contacting the server themselves?
Do "normal" applications somehow know that if there is nothing in /etc/resolv.conf that they should do a lookup on localhost port 53?
I suppose that testing it with nslookup is not a good example as it isn't exactly a "normal" application, or is it?


dieselnutjob
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Joined: 2011-04-12 10:25

Re: how does DNS work with systemd connman lxqt in sid?

#10 Post by dieselnutjob »

another useful command

Code: Select all

@macbookpro83:~# service --status-all
 [ - ]  anacron
 [ + ]  apparmor
 [ + ]  avahi-daemon
 [ + ]  bluetooth
 [ + ]  connman
 [ - ]  console-setup.sh
 [ + ]  cron
 [ + ]  dbus
 [ + ]  dundee
 [ + ]  haveged
 [ - ]  hwclock.sh
 [ + ]  irqbalance
 [ - ]  keyboard-setup.sh
 [ + ]  kmod
 [ + ]  networking
 [ + ]  ofono
 [ + ]  procps
 [ + ]  rsyslog
 [ + ]  sddm
 [ + ]  ssh
 [ - ]  sudo
 [ + ]  udev
 [ - ]  x11-common
this tells me that I have no rdnssd, no resolvconf and no NetworkManager services running

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