[Dnsmasq-discuss] dnsmasq not providing a response to client

[Albert ARIBAUD]

Hello Bill,

Le Tue, 6 Sep 2016 19:17:56 -0400
Bill Warren <billwarren at gmail.com> a écrit:

> Greetings from a new user of dnsmasq v.2.76 on FreeBSD v.10.3
> 
> dnsmasq is receiving queries and obtaining responses (confirmed in
> --no-daemon mode).

Rather than paraphrasing the dnsmasq output, can you copy-paste it,
including [a reasonable amount of] the lines which you think are
irrelevant? I'm asking this because in your description, you don't
indicate what dnsmasq says about the response once it got it from the
upstream (I don't think it discards it, but hey, troubleshooting is
about checking what you don't think can go wrong).

> However, the client never receives a response ...
> 	dig @192.168.1.14 www.google.com
> results in
> 	[…]
> 	connection timed out; no servers could be reached
> 
> I disabled the pf firewall to ensure it wasn’t filtering traffic, to
> no avail.

What about the server? Can you try dig on the same machine as dnsmasq
is running? Especially considering this:

> I cannot figure out why my clients aren’t getting the response from
> dnsmasq even though it received and looked-up the query.  

So it affects several clients. All the more a reason to check whether
the dnsmasq server itself can dig its own dnsmasq.

> Any suggestions would be greatly appreciated!  I stumbled onto
> dnsmasq and think it will be the perfect solution … once I get it
> working properly.

In addition to trying dig on the server itself, I also suggest doing a
tcpdump on the server machine's interface while doing the dig, in order
to cross-check whether the server process physically sends the response
out.

Then, same with digging from a client, but running two tcpdumps: one on
the server's physical interface, and one on the client's physical
interface.

(Ideally, you should either copy-paste tcpdump output here if it's
short enough (but complete enough!), or write the dumps to files through
option -w or stdout redirection and make the files available somewhere,
providing just the URLs.)

Amicalement,
-- 
Albert.