[Dnsmasq-discuss] Logging milliseconds

Albert ARIBAUD albert.aribaud at free.fr
Tue Jun 21 16:36:12 BST 2016


Bonjour,

Le Tue, 21 Jun 2016 16:41:02 +0200
<mabra at manfbraun.de> a écrit:

> Hello !
> 
> Ok, for a short moment, this might be ok.

Why 'for a short moment'? The only limit is storage for the tcpdump
dump to file, and that's relatively dense. Even if the machine on which
you are running tcpdump does not have enough storage space, it could
always send the output over the network to e.g. your desktop or laptop
machine, which is certainly able to handle it.

> But request/response usually
> dont follow each other directly, because there are some more of them
> "on the road". DNSMasq has already all this internally, while
> externally, one must really write a piece of tracker, which is able
> to wait for the answer of each request. Not a nice bash onliner .. ;-)

Wireshark is able to map responses to requests; in fact, in the packet
display window, it provides clickable links to jump from one to the
other. Wireshark also computes the time elapsed between request and
response, and displays it in the response packet. And you can export
all this as text, including references between requests and responses
and their time deltas.

Granted, if you want to do stats on long capture logs (or just limit
the dump to what you think is valuable), you'll have to write some ad
hoc AWK or sed lines, but I'd suspect a few tens at most, and nothing
more complex than variable assignments, some arithmetic, and ouput
formattting.

> But my question was just, if something like a format statement for the
> logoutput exists. It this exist (and I do not see it) then everything
> is already done.

I don't think there is any log format control option in dnsmasq.

> It's because I see huge delay for apps nearly each day. The provider
> declared to have the issue fixed. Sort of. The port are not longer
> blocked - but now, there are huge delay. The may probably have
> a contract with the NSA .... ;-)

"Delays in apps" can have so many causes. What possible causes other
than remote DNS servers have you considered and how did you rule them
out?

> Thanks anyway,
> 
> Manfred

Amicalement,
-- 
Albert.



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