[Dnsmasq-discuss] Re: Possible instability of DNS in 2.45
simon at thekelleys.org.uk
Tue Aug 19 09:42:14 BST 2008
Rune Kock wrote:
> On Wed, Aug 13, 2008 at 02:30, Rune Kock <rune.kock at gmail.com> wrote:
>> After running fine for over a week, my router with dnsmasq 2.45 became
>> very unwilling to answer DNS queries (only a few succeeded). Dumping
>> the statistics showed that a significant number of upstream queries
>> had failed. Restarting the router solved the problem.
> Thanks for the bug-hunting ideas, Simon and David.
> It turns out that my remote logging was horribly broken. (I wasn't
> aware that the machine receiving the log-entries would do a reverse
> dns-lookup to the router for every entry received -- and on the router
> I had enabled logging of all incoming connections!).
> With this kind of craziness going on, it seems very unlikely that
> dnsmasq was the cause of the problems. Really, what puzzles me the
> most is that things did actually work for some time.
Yes, I've seen this before. It's possible to end up with a situation
where every DNS query logs enough stuff to trigger more than one extra
query. That blows up very quickly. The asynchronous logging stuff in
dnsmasq was added at least in part as an attempt to keep things going in
pathalogical cases. I think syslog-ng can do local DNS caching which
> So my apologies for wasting your time. I have fixed the logging, and
> everything seems to be running perfectly now.
No problem, thanks for reporting back.
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