What is the best place to find further documentation on this? (Or, do you
have a recommended setup?)

All I'm able to find is
http://www.eecis.udel.edu/~mills/ntp/html/accopt.html which suggests that
"limited" may have no effect unless a "discard" line is specified as well.
I'm curious what the recommended values are for that.

Incidentally, on Fedora/CentOS/RHEL, the default is the same as mentioned
on Debian -- the "kod" restriction is present, but "limited" is not. (And
the "Secure NTP Template" on Team Cymru's site makes no mention of "kod" or
"limited".)

-- Matt

On Sat, Jun 23, 2012 at 11:36 PM, Dave Hart <[email protected]> wrote:

> Ted, your posted ntp.conf has:
>
> restrict -4 default kod notrap nomodify nopeer noquery
> restrict -6 default kod notrap nomodify nopeer noquery
>
> If you're using ntpd 4.2.6 or later, you can consolidate that into a
> single line omitting -4/-6.  In any case, please consider adding
> "limited" to your default restrictions, so that clients are
> rate-limited and your server is less useful for spoofed-source-address
> reflection attacks.  Without "limited", the "kod" is useless -- it
> controls only how ntpd responds to rate limit exceeded, but first you
> have to have "limited" to enforce the rate limit.
>
> Cheers,
> Dave Hart
> _______________________________________________
> pool mailing list
> [email protected]
> http://lists.ntp.org/listinfo/pool
>
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