[Dnsmasq-discuss] DNS refused when internet is down

[Matus UHLAR - fantomas]

>>>On 11/25/2020 9:31 AM, Duncan Webb wrote:
>>>>When the internet is down for some external reason nslookup is returning
>>>>"Connection to DNS 10.0.0.1 was refused" when looking up a host on the
>>>>LAN that has its IP from DHCP. Both DHCP and DNS are provided by 
>>>>dnsmasq.
>>>>
>>>>Is this the expected behaviour or a misconfiguration?

>>On Wed, Nov 25, 2020 at 10:44:34AM +0100, john doe wrote:
>>>No, this is not the expected behavior.

>On 26/11/2020 08:31, Geert Stappers wrote:
>>Also my first impression, on second thought: "It could be" ...

>>>We can not say
>>>where the issue lies with the little information you have provided.

>>So please make your problem an interesting challenge for the ML ;-)

On 01.12.20 09:32, Duncan Webb wrote:
>The problem can be reproduced by disconnecting the cable to the ADSL 
>router. As soon as the cable is removed then a nslookup will return a 
>"Connection to DNS 10.0.0.1 was refused" reply for every query.

which server does 10.0.0.1 belong to?  apparently not to your router, as
I don't see this address as argument to --listen-address.

>I would expect that hosts on the LAN that have been provided an IP 
>address from the dnsmasq DHCP server to resolve.

hosts on the lan should be resolved by dnsmasq, but unreachable address
can't resolve them.

>The configuration is all on the command line and this is
>
>/usr/local/sbin/dnsmasq --all-servers -H /var/etc/dnsmasq-hosts
>--listen-address=192.168.0.254 --listen-address=10.99.2.1
>--listen-address=10.99.0.1 --listen-address=10.99.128.1
>--listen-address=127.0.0.1 --listen-address=::1 --bind-interfaces
>--server=/example.net/10.99.0.1 --server=/opcase.private/10.99.130.1
>--server=/130.99.10.in-addr.arpa/10.99.130.1
>--server=/opcase1.private/10.99.144.1
>--server=/144.99.10.in-addr.arpa/10.99.144.1 --dns-forward-max=5000
>--cache-size=10000 --local-ttl=1
>--conf-dir=/usr/local/etc/dnsmasq.conf.d,*.conf
>
>I don't think that the options --server=/opcase.private/10.99.130.1 
>where the server is offline could be causing this but for completeness 
>both the servers 10.99.130.1 and 10.99.144.1 are offline.
>
>The --conf-dir directory has no .conf files.
>
>The firewall is OPNsense which based on BSD and I don't think this is 
>relevant to this specific problem.
>
>example.net is not the real domain. The contents of 
>/var/etc/dnsmasq-hosts contains lines like this:
>
>10.99.0.201 w1.example.net w1
>10.99.0.202 w2.example.net w2
>10.99.0.203 w3.example.net w3
>
>It is these addresses that I would expect to be resolved.

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Matus UHLAR - fantomas, uhlar at fantomas.sk ; http://www.fantomas.sk/
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