[atlas] Big latency change

On 2015-05-15 18:28, Daniel Baeza (Red y Sistemas TVT) wrote:
> Hi folks,
> 
> How can I check what happened at 13:00 (Dont know if the time in my probe is
> UTC or UTC+2) of today in the a.root-servers.net?
> 
> My latency with the a-root changed from 117 to 45ms and Im curious of what
> happened.
> 
> I've took a look in the RIPEstat routing for the IP Address of the root
> server, and at the same time the BGP had changes, but there are too many AS
> involved I cant follow it.
> 
> 
> Thanks in advance!

Hi,

a-root is anycasted, so most likely your probe switched to a different
instance of the server. You can see their instances here:
https://atlas.ripe.net/contrib/root_anycast.html?msm_id=9

You can check dns measurements your probe does and see if this is indeed the
case -- they are available to you in the probe status page, built-in
measurements tab. Perhaps "v4 DNS to a.root-servers.net (UDP hostname.bind)"
is the best to try. Similarly, traceroutes could tell you exactly what changed.

(We report all times in UTC)

Cheers,
Robert