nanog mailing list archives

Re: OpenNTPProject.org


From: Brian Rak <brak () gameservers com>
Date: Mon, 17 Feb 2014 08:45:32 -0500

Rate limitings been in place for quite some time, but I believe it's only for actual time queries. This DDOS uses monlist, which isn't subject to the same rate limits.

You've disabled monlist now, so I bet you'll no longer need all the rate limiting IPTables rules. (Though, you'll still see the incoming garbage for awhile, but NTPD will just discard it so it shouldn't cause problems).

On 2/17/2014 2:23 AM, Pete Ashdown wrote:
On 2/16/14, 7:38 PM, Brian Rak wrote:
Seriously, just fix your configuration.  The part of NTP being abused
is completely unrelated to actually synchronizing time.  It's a
management query, that has no real reason to be enabled remotely. You
don't even need to resort to iptables for this, because NTPD has built
in rate limiting (which isn't enabled for management queries, but
those are trivial to disable).
Thanks for the tip, monitoring is off.  I was under the impression that
rate-limiting hadn't made it into a stable version of ntpd yet.  Is that
incorrect?





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