[dns-operations] Storm on the DNS
bortzmeyer at nic.fr
Tue Dec 1 08:15:11 UTC 2015
On Tue, Dec 01, 2015 at 11:07:01AM +0800,
Song Linjian (Davey) <songlinjian at gmail.com> wrote
a message of 188 lines which said:
> In the monitoring page the red block means unanswered packets ratio
> >70%, right ?
Yes. The default value of DNSmon is very high, but you can change it.
> I wondering the root server instance in that red region is up or
> down? if it is still up, the queries can not be routed to other
> server where the the probes shows green.
The server is up but unresponsive because of the load. As a result
most resolvers switch to another letter. (A few servers like A never
had a problem or may be were not attacked.)
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