[Dnsmasq-discuss] Problem with no-resolv and no IP

[Alkis Georgopoulos]

Hello Donald,

aren't bind-dynamic and bind-interfaces for people that have multiple 
services in the 53 port?
I have a single dnsmasq running, and it's listening on 0.0.0.0:53, i.e. 
on "all interfaces", shouldn't it be answering?

I think it's a wrong initialization bug somewhere in the code that 
decides when dnsmasq should answer. Configuration workarounds do exist, 
but I feel that it's a bug that should be resolved by updating the 
dnsmasq codebase.

Thanks,
Alkis

On 3/6/22 05:35, Donald Muller wrote:
> I think you need to enable
> 
> --bind-dynamic
> Enable a network mode which is a hybrid between --bind-interfaces and the default. Dnsmasq binds the address of individual interfaces, allowing multiple dnsmasq instances, but if new interfaces or addresses appear, it automatically listens on those (subject to any access-control configuration). This makes dynamically created interfaces work in the same way as the default. Implementing this option requires non-standard networking APIs and it is only available under Linux. On other platforms it falls-back to --bind-interfaces mode.
> 
>> -----Original Message-----
>> From: Dnsmasq-discuss <dnsmasq-discuss-bounces at lists.thekelleys.org.uk>
>> On Behalf Of Alkis Georgopoulos
>> Sent: Saturday, March 5, 2022 4:46 PM
>> To: dnsmasq-discuss at lists.thekelleys.org.uk
>> Subject: [Dnsmasq-discuss] Problem with no-resolv and no IP
>> 
>> Hi, on Ubuntu 22.04 and dnsmasq 2.86-1.1:
>> 
>> 1) Use the following dnsmasq.conf:
>> no-resolv
>> server=8.8.8.8
>> 2) Ifdown the network so that there's no local IP
>> 3) (Re)start dnsmasq
>> 4) Ifup the network, let's say local IP=10.0.0.1 now
>> 
>> At that point:
>> 5) `host google.com 10.0.0.1` fails with connection timed out,
>> 6) `host google.com 127.0.0.1` works.
>> 
>> In other words, when dnsmasq is started when there's no local IP, AND
>> no-resolv is set, then dnsmasq doesn't reply to the local IPs that are
>> assigned later on.
>> 
>> Is this a bug? Am I doing something wrong?
>> Please Cc me as I'm not subscribed to the list.
>> 
>> Thank you,
>> Alkis Georgopoulos
>> 
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