[atlas] Request to test TCP and UDP to the root servers separately.

Hello,

This is an older thread, but since we made some enhancements in the
meantime, it could be worth picking it up again.

On 2012.02.26. 16:36, Leo Bicknell wrote:
> In a message written on Sat, Feb 25, 2012 at 10:49:04AM +0100, Philip Homburg wrote:
>> On 2/24/12 21:41 , Leo Bicknell wrote:
>>> Would it be of interest to the Atlas community to have the probes
>>> try and query "." via both UDP and TDP from each of the 13 root
>>> servers (perhaps v4 and v6 separately), report back that data, and
>>> then generate a report on the results?  I would be happy to assist
>>> in preparing or presenting a report on the results!
>>>
>> The probes are already measuring this. I don't think we made any graphs 
>> of the results.

In case you've missed the recent announcement: we're now visualising more of
the "latest DNS root measurements" here:
https://atlas.ripe.net/contrib/root_anycast.html?msm_id=1

Basically, we do queries from all the probes for the serial in the SOA to
all root servers, over IPv4 and IPv6, using UDP and TCP. The above
visualisation now shows these too. We also have all the historical results
of these. Taking this into account:

> I'm not sure a graph would be the best representation of this data.  The
> interesting questions to me are:
> 
> - Compare Failure Levels
>   - What is the overall level of UDP failure?
>   - What is the overall level of UDP+EDNS0 failure?
>   - What is the overall level of TCP failure?

TCP+UDP are possible, EDNS0 not yet.

> - Exploring the differences in the ecosystem
>   - Is there a statistical difference in the failure rate between IPv4 and
>     IPv6?  (Are we getting better or worse)
>   - Is there a statistical difference in the failure rate between two
>     different root servers?  (Does the root server deployment model
>     matter)
>   - What is the difference in response time of TCP queries compared to UDP
>     queries? (What's the penalty to fall back to TCP)

These are also possible. It's not trivial, as there are some artefacts to be
taken into consideration (anycast instance switches, some nodes not
responding to some queries, etc.), but it is possible in general.

We're not yet ready with the Atlas data sharing facility, but the data is
available on request. Let us know if you're really interested in doing this
analysis. We can also discuss this at the upcoming RIPE meeting, with
whoever is there :-)

Cheers,
Robert