Removed Pihole; cannot start new container listening on port 53

[doesntaffect]

I removed Pihole (container, image, template) since it seem to be related to DNS issues in my network.

Then I created an Adguard container which cannot start now since port 53 is still being occupied. 

 

Question - by what / which service?

 

The docker engine throws this error when I create the container: 

 

docker: Error response from daemon: driver failed programming external connectivity on endpoint AdGuard-Home (b2fa2aa7baac63aa19aa0c4fbd4b9555fd2f034bac110b646683a171bb6bea29): Error starting userland proxy: listen tcp4 0.0.0.0:53: bind: address already in use.

 

Any advise how this can be fixed? 

 

A netstat on the host show this, and I don't see any container listening on 53.

 

netstat -pna | grep 53
tcp        0      0 0.0.0.0:5355            0.0.0.0:*               LISTEN      27171/wsdd2         
tcp        0      0 0.0.0.0:3443            0.0.0.0:*               LISTEN      30538/docker-proxy  
tcp        0      0 0.0.0.0:4533            0.0.0.0:*               LISTEN      30022/docker-proxy  
tcp        0      0 192.168.122.1:53        0.0.0.0:*               LISTEN      10590/dnsmasq       
tcp        0      0 192.168.178.249:80      192.168.178.54:53460    TIME_WAIT   -                   
tcp        0      0 192.168.178.249:80      192.168.178.54:53550    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53389    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53497    TIME_WAIT   -                   
tcp        0      0 192.168.178.249:80      192.168.178.54:53555    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53556    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53390    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53557    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53553    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53554    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53388    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53387    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53499    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53558    ESTABLISHED 7399/nginx: worker  
tcp        0     14 192.168.178.249:80      192.168.178.54:53561    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53552    ESTABLISHED 7399/nginx: worker  
tcp        0      0 192.168.178.249:80      192.168.178.54:53551    ESTABLISHED 7399/nginx: worker  
tcp6       0      0 :::4533                 :::*                    LISTEN      30029/docker-proxy  
udp        0      0 0.0.0.0:5353            0.0.0.0:*                           27191/avahi-daemon: 
udp        0      0 0.0.0.0:5355            0.0.0.0:*                           27171/wsdd2         
udp        0      0 192.168.122.1:53        0.0.0.0:*                           10590/dnsmasq       
udp6       0      0 :::5353                 :::*                                27191/avahi-daemon: 
unix  2      [ ACC ]     STREAM     LISTENING     153014   30047/containerd-sh  /run/containerd/s/28ec7daac2528544a3768842fc90f52ffe93983dd533109f5b0b26ef918f62c5
unix  2      [ ACC ]     STREAM     LISTENING     148264   30559/containerd-sh  /run/containerd/s/b7888a0669bb979537068e146779ff32858ff0a3e20c60dd4bda6eea39620139
unix  2      [ ACC ]     STREAM     LISTENING     149187   31565/containerd-sh  /run/containerd/s/68f150ffeb953dca02559017754040e3b6b3bfe77f7cee2f65636bc58a86e4da
unix  3      [ ]         STREAM     CONNECTED     159931   30559/containerd-sh  /run/containerd/s/b7888a0669bb979537068e146779ff32858ff0a3e20c60dd4bda6eea39620139
unix  3      [ ]         STREAM     CONNECTED     153184   27298/containerd     
unix  3      [ ]         STREAM     CONNECTED     159753   28168/containerd-sh  /run/containerd/s/5ec104dec6088fbefa7b61744247a6dd13c9bf6d90a40e3e7555bd447c1b5588
unix  3      [ ]         STREAM     CONNECTED     159911   30047/containerd-sh  /run/containerd/s/28ec7daac2528544a3768842fc90f52ffe93983dd533109f5b0b26ef918f62c5
unix  3      [ ]         STREAM     CONNECTED     148368   31565/containerd-sh  /run/containerd/s/68f150ffeb953dca02559017754040e3b6b3bfe77f7cee2f65636bc58a86e4da

 

 

[Squid]

Generally, piHole / AdGuard and the like you would have running on their on dedicated IP address so that there is no problem.  The docker run command's error reflects every port, not simply a port another container is doing.

 

If you've switched it to bridge mode, then there are other ports already in use for one reason or another via the OS and all conflicting ports would need to be resolved (eg: 53)

[theruck]

the problem is the conflict from the virbr0 interface 192.168.122.1:53 which shall not exist in the first place but its somehow by default listening on port 53 once the libvirt service is started

there is nothing in the libvirt configs regarding that port 53 so it looks to be caused by the dnsmasq package

 

Edited June 10, 2022 by theruck