[Dnsmasq-discuss] Mac Darwin confusion [solved]

[Bernd Prager]

On 8/4/20 6:01 PM, Geert Stappers wrote:
> On Tue, Aug 04, 2020 at 08:18:24AM +0700, Bernd Prager wrote:
>> On 8/4/20 3:36 AM, Andrew Miskell wrote:
>>> On Aug 3, 2020, at 3:06 PM, Geert Stappers <stappers at stappers.nl> wrote:
>>>> On Mon, Aug 03, 2020 at 07:04:47PM +0200, No Yes No Questions wrote:
>>>>> On Mon, Aug 03, 2020 at 10:44:07PM +0700, Bernd Prager wrote:
>>>>>> Hi all,
>>>>>>
>>>>>> I got something I can't wrap my head around. I have a QNAP NAS that I
>>>>>> thought would be nice for hosting a DNSMASQ service for DNS and DHCP. Setup
>>>>>> went smooth and all my Linux clients behave wonderfully, except my Mac
>>>>>> client:
>>>>>>
>>>>>> Querying a host from Linux goes perfect:
>>>>>>
>>>>>> -=[22:29:35][bernd at hoenir ~]=- dig @qnap freyja
>>>>>>
>>>>>> ;; QUESTION SECTION:
>>>>>> ;freyja.                                IN      A
>>>>>>
>>>>>> ;; ANSWER SECTION:
>>>>>> freyja.                 0       IN      A 192.168.1.7
>>>>>>
>>>>>> ;; Query time: 0 msec
>>>>>> ;; SERVER: 192.168.1.5#53(192.168.1.5)
>>>>> .5
>>>>>
>>>>>
>>>>>> -=[22:29:37][bernd at hoenir ~]=-
>>>>>>    ping -c 1 freyja
>>>>>> PING freyja.prager.homeip.net (192.168.1.7) 56(84) bytes of data.
>>>>>> 64 bytes from freyja.prager.homeip.net (192.168.1.7): icmp_seq=1 ttl=64
>>>>>> time=131 ms
>>>>>>
>>>>>> --- freyja.prager.homeip.net ping statistics ---
>>>>>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
>>>>>> rtt min/avg/max/mdev = 131.374/131.374/131.374/0.000 ms
>>>>>>
>>>>>> Now the same query from my Mac sees the host but still can't connect to it:
>>>>>>
>>>>>> [bernd at loki ~$ dig @qnap freyja
>>>>>>
>>>>>> ;; QUESTION SECTION:
>>>>>> ;freyja.                IN    A
>>>>>>
>>>>>> ;; ANSWER SECTION:
>>>>>> freyja.            0    IN    A    192.168.1.7
>>>>>>
>>>>>> ;; Query time: 7 msec
>>>>>> ;; SERVER: 192.168.1.5#53(192.168.1.5)
>>>>> The same .5
>>>>>
>>>>>> [bernd at loki ~$ ping -c 1 freyja
>>>>>> ping: cannot resolve freyja: Unknown host
>>>>>>
>>>>>> Does anybody have an idea what I am missing?
>>>>> Yes
>>>>>
>>>> DNS query tool `dig` at the Linux system does add domain name to the request.
>>>>
>>>> `dig` at the MacOS system doesn't add a domain name, which is correct behaviour.
>>>>
>>>>
>>>> For `ping` is it OK to add a domainname. It seems the Mac is not aware
>>>> of domain name.
>>>>
>>>> Find a way to tell the Mac about the .prager.homeip.net domain name.
>>>>
>>> macOS will know about the domain if it’s told by the DNS server via DHCP.
>>>
>>> However, macOS will cache information and sometimes will need a
>>> forced reset to pick things up. Using "dscacheutil -flushcache;sudo
>>> killall -HUP mDNSResponder” should reset the DNS cache on macOS.
>>>
>>>
>>
>> Thank you all for your kind help. I wanted to give the list a quick update:
>>
>> While I have not resolved the issue yet, despite trying all the suggestions
>> above (except Geert's ".5" comment which I need to do some research on what
>> that actually means),
>>>>>> ;; SERVER: 192.168.1.5#53(192.168.1.5)
>>>>> .5
>>>>>> ;; SERVER: 192.168.1.5#53(192.168.1.5)
>>>>> The same .5
> The last octet of the IPv4 address.
>
>
>> I have nailed the likely culprit to the NordVPN I have
>> running with my particular user. Pinging my other Intranet-Hosts from any
>> other user on my Mac without the VPN running actually works. It seems that
>> the VPN does something to my network configuration that its not telling me.
>> The Mac DNS utility still claims to point to my DNSMASQ instance.
>>
>> By the way, pinging my internal host with a full domain name
>> freyja.prager.homeip.net resolves to my DynDNS external network IP address.
>
> Nice, please explore it further, you learn a lot from it.
>
>
>
> Groeten
> Geert Stappers

Hi everyone,

I wanted to reveal the solution to my problem in case someone else 
stumbles upon this:

The root cause of my issue was apparently the NordVPN client taking over 
all system DNS handling, suppressing each and every system setting and 
configuration.

At the advise of NordVPN support I stopped using their Mac client and 
started using Tunnelblick instead.

Now everything works as expected.

Thank you again for all your support.

Cheers,
-- Bernd