[Dnsmasq-discuss] Problem with 127.0.1.1 versus 127.0.0.1

[Petr Menšík]

What is specified in dnsmasq does not matter. host by default does not 
talk to dnsmasq directly. It reads /etc/resolv.conf and uses nameserver 
specified there. If that is IP of dnsmasq, okay. If it is not, well, the 
problem might be elsewhere. Because I don't know what is there, I cannot 
help.

If you do "dig @localhost jacquibennett.com", then you are asking 
dnsmasq explicitly. Just "dig jacquibennett.com" uses server in 
/etc/resolv.conf, which may not even contain localhost address at all. 
That is why I have asked what is there.

On 17. 07. 23 9:00, Chris Green wrote:
> On Sun, Jul 16, 2023 at 11:58:38PM +0200, Petr Menšík wrote:
>> I think you have failed to show us what is in /etc/resolv.conf on the
>> machine, which is running host command.
>>
> It's specified in /etc/dnsmasq.conf:-
>
>      resolv-file=/run/NetworkManager/no-stub-resolv.conf
>
> ... and the contents are:-
>
>      # Generated by NetworkManager
>      search zbmc.eu
>      nameserver 192.168.1.2
>
>> unless listen-address or interface is specified, it should listen on all
>> interfaces.
>>
> Yes, that's what I thought.
>
>
>> Try using host -v jacquibennett.com, it might provide more details what
>> exactly has timed out.
>>
>> If unsure what is host contacting, try separate queries to server
>> specified explicitly:
>>
>> - host -v jacquibennett.com 127.0.0.1
>> - host -v jacquibennett.com 127.0.1.1
>>
>> That might provide hints what is failing and what is working.
>>
> Ah, thank you, I hadn't thought to check options for the host command,
> I had been using dig to look deeper.
>
> Typically when I tried just now both the above host commands worked
> instantly with no errors!  I'll have to keep trying to work out what's
> wrong.
dig is better tool anyway, stay using that. host returns more compact 
result, but is worse tool when hunting strange errors. Mostly because 
without -t parameters it does 3 queries and possibleerror does not have 
clear indication, to which it belongs.
>
>> Cheers,
>> Petr
>>
>> On 7/16/23 22:10, Chris Green wrote:
>>> I use dnsmasq on a number of, mostly Ubuntu, home systems. One system
>>> at 192.168.1.2 acts as the DNS server for my LAN, then there are
>>> several 'client' systems that just use dnsmasq as a caching DNS server
>>> for their own lookups.
>>>
>>> I *suspect* I have a problem with looking up names via the local
>>> dnsmasq because it is listening only on 127.0.1.1 and the request is
>>> on 127.0.0.1#53.
>>>
>>> for example a 'host'command on my laptop returns:-
>>>
>>>       chris$ host jacquibennett.com
>>>       ;; communications error to 127.0.0.1#53: timed out
>>>       jacquibennett.com has address 153.92.6.161
>>>       jacquibennett.com has IPv6 address 2a02:4780:a:1080:0:174b:7855:7
>>>       jacquibennett.com mail is handled by 5 mx1.hostinger.com.
>>>       jacquibennett.com mail is handled by 10 mx2.hostinger.com.
>>>
>>> But dnsmasq is running on the laptop:-
>>>
>>> dnsmasq 7443 1 0 09:27 ? 00:00:01 /usr/sbin/dnsmasq -x /run/dnsmasq/dnsmasq.pid
>> -u dnsmasq -7 /etc/dnsmasq.d,.dpkg-dist,.dpkg-old,.dpkg-new --local-service
>> --trust-anchor=.,20326,8,2,e06d44b80b8f1d39a95c0b0d7c65d08458e880409bbc683457104237c7f8ec8d
>>
>>>
>>> The dnsmasq configuration file on the laptop (and other client
>>> systems) is almost non-existent, it's just:-
>>>
>>>       resolv-file=/run/NetworkManager/no-stub-resolv.conf
>>>
>>> ... /run/NetworkManager/no-stub-resolv.conf is:-
>>>
>>>       # Generated by NetworkManager
>>>       search zbmc.eu
>>>       nameserver 192.168.1.2
>>>
>>>
>>> ... and in /etc/dnsmasq.d I just have a blacklist file with lots of
>>> address=<something> entries, but that's all.  The /etc/default/dnsmasq
>>> file just has:-
>>>
>>>       ENABLED=1
>>>       CONFIG_DIR=/etc/dnsmasq.d,.dpkg-dist,.dpkg-old,.dpkg-new
>>>
>>>
>>> So why do I get that timeout error from the 'host' coommand? It's as
>>> if dnsmasq on the local machine isn't listening on 127.0.0.1.  Does it
>>> only listen on 127.0.1.1 by default?
>>>
>> -- 
>> Petr Menšík
>> Software Engineer, RHEL
>> Red Hat, https://www.redhat.com/
>> PGP: DFCF908DB7C87E8E529925BC4931CA5B6C9FC5CB

-- 
Petr Menšík
Software Engineer, RHEL
Red Hat, http://www.redhat.com/
PGP: DFCF908DB7C87E8E529925BC4931CA5B6C9FC5CB