[atlas] Using Atlas for Monitoring of Anycast DNS

Klaus and other RIPE Atlas folks,

One thing that I noticed is that it is almost impossible to have enough 
Atlas credits to do operational monitoring of an anycast DNS setup. This 
is because in order to have enough credits to get timely checks you need 
to have many times as many probes as sites to check.

This is not to say that RIPE Atlas is not a helpful and useful tool, but 
I think it can only be an additional source of information for your main 
monitoring setup.

Cheers,

--
Shane

On 17/01/2020 17.41, Klaus Darilion wrote:
> Looks like a nice tool. Thanks for the hint.
> Klaus
> 
> Am 16.01.2020 um 16:45 schrieb Stephane Bortzmeyer:
>> On Thu, Jan 16, 2020 at 04:33:47PM +0100,
>>   Klaus Darilion <klaus.mailinglists at pernau.at> wrote
>>   a message of 48 lines which said:
>>
>>> - analyze the probe locations (ie. country, continent)
>>
>> Instead of analyzing it afterwards, why not directly asking probes on
>> the place you're interested in?
>>
>> I often use NSID to watch anycast servers, indeed:
>>
>> % blaeu-resolve --requested 100 --area West --nameserver $(dig +short +nodnssec d.nic.fr A) --type SOA --nsid --displayrtt fr
>> Nameserver 194.0.9.1
>> [NSID: b'dns.th2.nic.fr' nsmaster.nic.fr. hostmaster.nic.fr. 2225269298 3600 1800 3600000 5400] : 34 occurrences Average RTT 146 ms
>> [NSID: b'dns.fra.nic.fr' nsmaster.nic.fr. hostmaster.nic.fr. 2225269298 3600 1800 3600000 5400] : 3 occurrences Average RTT 100 ms
>> [NSID: b'dns.nyc.nic.fr' nsmaster.nic.fr. hostmaster.nic.fr. 2225269298 3600 1800 3600000 5400] : 35 occurrences Average RTT 56 ms
>> [NSID: b'dns.ix1.nic.fr' nsmaster.nic.fr. hostmaster.nic.fr. 2225269298 3600 1800 3600000 5400] : 4 occurrences Average RTT 116 ms
>> [TIMEOUT] : 2 occurrences Average RTT 0 ms
>> [NSID: b'dns.mrs.nic.fr' nsmaster.nic.fr. hostmaster.nic.fr. 2225269298 3600 1800 3600000 5400] : 10 occurrences Average RTT 156 ms
>> [NSID: b'dns.ams.nic.fr' nsmaster.nic.fr. hostmaster.nic.fr. 2225269298 3600 1800 3600000 5400] : 8 occurrences Average RTT 101 ms
>> [NSID: b'dns.lon.nic.fr' nsmaster.nic.fr. hostmaster.nic.fr. 2225269298 3600 1800 3600000 5400] : 2 occurrences Average RTT 154 ms
>> [nsmaster.nic.fr. hostmaster.nic.fr. 2225269297 3600 1800 3600000 5400] : 1 occurrences Average RTT 24 ms
>> Test #23843409 done at 2020-01-16T15:43:10Z
>>
>> Note the wonders of BGP: only a minority of probes use the instance in
>> New York City (the fastest one) :-(
>>
>> Note also that the last result comes from a transparent proxy,
>> redirecting to a cache.
>>
>