2017-11-23 9:56 GMT+01:00 Michael Meier <michael.meier@fau.de>:

Those times are reproducible, a machine will always get the same 15 or
10 or 4 ms ping. So their anycasted 9.9.9.9 seems to internally redirect
queries based on source-IP-hash, and if you're unlucky, they redirect
you to a server at the other end of the continent, that has a latency
that is worse than if you used a DNS in another european country.

Hi All,

I think Quad9 uses round robin dns with server pools (3?) behind 9.9.9.9 anycast address: 

My findigs: 

$ for i in $(seq 0 9); do echo -n "$i "; dig +short @9.9.9.9 hostname.bind txt CH; sleep 3; done

 0 "res300.ams.rrdns.pch.net"
 1 "res300.ams.rrdns.pch.net"
 2 "res100.ams.rrdns.pch.net"
 3 "res200.ams.rrdns.pch.net"
 4 "res200.ams.rrdns.pch.net"
 5 "res200.ams.rrdns.pch.net"
 6 "res300.ams.rrdns.pch.net"
 7 "res200.ams.rrdns.pch.net"
 8 "res300.ams.rrdns.pch.net"
 9 "res300.ams.rrdns.pch.net" 

... Quand9  dns server are not created equal:

$ for i in $(seq 0 9); do echo -n "$i "; dig +short @9.9.9.9 version.bind txt CH; sleep 3; done

 0 "Q9-U-5.0"
 1 "Q9-P-5.0"
 2 "Q9-U-5.0"
 3 "Q9-P-5.0"
 4 "Q9-P-5.0"
 5 "Q9-U-5.0"
 6 "Q9-P-5.0"
 7 "Q9-P-5.0"
 8 "Q9-P-5.0"
 9 "Q9-P-5.0"

E.
--
| ENRICO ARDIZZONI
| Responsabile Ufficio Reti e Sistemi
| Università degli Studi di Ferrara