[Dnsmon-test] retries of DNS queries
Gilles Massen
gilles.massen at restena.lu
Thu Feb 13 17:29:32 CET 2014
Hi,
On 02/13/2014 05:16 PM, Chris Amin wrote:
> In addition, we have changed a line in the testers page in the section
> comparing the old and the new DNSMON implementations. We previously
> stated that the RIPE Atlas measurements are not retried on failure
> (whereas the old TTM boxes do carry out retries). However, RIPE Atlas
> has gained the ability to carry out an arbitrary number of retries, and
> uses a value of 10 by default. The data that we have collected so far
> for the new DNSMON, and the visualisations, are therefore based on this
> methodology.
>
> We don't want to immediately change to using 0 retries, nor do we want
> to change to match the exact settings of the old DNSMON, without
> gathering feedback from you. So if you have a strong opinion on this,
> please let us know.
No strong opinion (yet), but a request for clarification: how do the
really late answers relate to retries? i.e. is a query is answered after
3s, does that mean that
a) an answer came in 3s after the first query and after an unknown
number of retries
or
b) the answer came 3s after the exact packet that asked the question?
(if retries use the same query id / source port the answer is probably
obvious...)
Best,
Gilles
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