9.18 behavior change for mDNS queries with dig

[Larry Stone]

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.

-- 
Larry Stone
lstone19 at stonejongleux.com





> On Jun 27, 2022, at 1:48 AM, Petr Špaček <pspacek at isc.org> wrote:
> 
> On 27. 06. 22 8:26, Evan Hunt wrote:
>> On Sun, Jun 26, 2022 at 10:00:08PM -0500, Larry Stone wrote:
>>> I recently moved from 9.16 to 9.18 and just noticed that dig no longer
>>> resolves mDNS queries.
>>> 
>>> With 9.16:
>>> dig +short @224.0.0.251 -p 5353 hostname.local
>>> 192.168.0.82
>>> 
>>> With 9.18:
>>> dig +short @224.0.0.251 -p 5353 hostname.local
>>> ;; connection timed out; no servers could be reached
>>> 
>>> I can’t find anything in the Release Notes (or anyplace else) about this.
>> "dig" was rewritten in 9.18 to use the libuv-based network manager
>> instead of the old socket code; it's probably related to that. Please
>> open a bug report at https://gitlab.isc.org/isc-projects/bind9/-/issues,
>> we'll look into it.
> 
> Please don't forget to attach PCAP file produced by tcpdump or similar tool so we can see if anything happens on the wire or not.
> 
> -- 
> Petr Špaček