9.18 behavior change for mDNS queries with dig

[Larry Stone]

Neither wireshark or nor tcpdump (AFAIK) can return the data in a form suitable for use in a shell script (my need was (emphasis on “was”, I’ve already re-worked my configuration to no longer need the lookup) get the current address of example.local and then use it in the shell script).

In any event, the bug report was submitted and the response was that dig was never intended to be used for mDNS queries and that it did until 9.18 was just luck. Changes made in 9.18 make it no longer work but since that was never a documented use of dig, there are no plans to make it work again. I am satisfied with that response and since my use of dig for mDNS lookups was legacy code in my script that was no longer needed (there was another way to accomplish the end goal of the script), it was a good excuse to clean up the script.

-- 
Larry Stone
lstone19 at stonejongleux.com





> On Jul 1, 2022, at 6:12 AM, Greg Choules via bind-users <bind-users at lists.isc.org> wrote:
> 
> Wireshark works just fine on a Mac (I am using it right now) and yes, it is a great tool. You also have the choice of using tcpdump in a terminal window, if that's your preference. Personally I usually capture using tcpdump and view later in Wireshark.
> 
> On Fri, 1 Jul 2022 at 12:01, Petr Menšík <pemensik at redhat.com> wrote:
> Wireshark is a great tool with a nice GUI, which can record you traffic 
> on selected ports. Just use capture filter port 5353. But I am not 
> certain it works on Mac just as it does not Linux.
> 
> On 6/27/22 15:10, Larry Stone wrote:
> > Petr, you are going to have to tell me how to create an appropriate PCAP file. As most of this stuff works so well these days, it’s been years since I had to do any sort of packet level analysis (moved on to other things professionally) and what I knew of how to do that has long since been lost. My issue is on a small home network so very little goes wrong. The appropriate tcpdump command to get what is needed should be all I need.
> >
> 
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