[ntp:questions] better rate limiting against amplification attacks?

Greg Troxel gdt at ir.bbn.com
Thu Jan 16 00:18:06 UTC 2014

[invalid William has been trimmed from the cc list] 

Harlan Stenn <stenn at ntp.org> writes:

> William Unruh writes:
>> I do not mean the default in the config file, I mean the default if
>> there is no config file or if nothing is set in the config file.
> Then ntpd won't connect to anything and there will be no data to report.

This is a ridiculous strawman.   The ntp project is abdicating its
responsibility to provide sane default behavior by claiming that no
default behavior can make everyone happy and therefore it's not their
fault.  The notion that OS packagers somehow have a better idea of usage
is also specious.

Really, ntpd should, when run with a config file of only

  server 0.pool.ntp.org
  server 1.pool.ntp.org
  server 2.pool.ntp.org

behave relatively sanely, including declining to respond to packets that
could be amplification attacks, while being usable as a s2/s3 to other
nearby nodes.  This notion of good behavior under minimal config seems
really obvious to me, yet there is a huge resistance to it, with the
notion that every end user should invest the time to be an expert.
And, as far as I can tell, seems to be as simple as 'restrict noquery'
as a compiled-in default before any restrict statements are given.  Yet
that does not happen.

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