[Dnsmasq-discuss] Mac Darwin confusion

[Andrew Miskell]

> 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
>>> 
>>> ; <<>> DiG 9.11.3-1ubuntu1.12-Ubuntu <<>> @qnap freyja
>>> ;; Got answer:
>>> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 24213
>>> ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
>>> 
>>> ;; 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
>> 
>> 
>>> ;; WHEN: Mon Aug 03 22:29:37 +07 2020
>>> ;; MSG SIZE  rcvd: 51
>>> 
>>> -=[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
>>> 
>>> ; <<>> DiG 9.10.6 <<>> @qnap freyja
>>> ;; Got answer:
>>> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 54217
>>> ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
>>> 
>>> ;; 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
>> 
>> 
>>> ;; WHEN: Mon Aug 03 22:29:25 +07 2020
>>> ;; MSG SIZE  rcvd: 51
>>> 
>>> [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.
> 
> 
> Groeten
> Geert Stappers
> -- 
> Silence is hard to parse
> 
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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.